بسم هللا الرحمن الرحيمbull

Sterilization and Disinfection

Dr Nadir Mehmood

Asstt Prof of Surgery

RMC

Learning ObjectivesAt the end of the discussion a student will be able to

bull Define terms in relation to topic

bull Classify methods of sterilization and disinfectives

bull Enumerate the merits of different methods

bull Indicate the choice of method for different instruments and procedures

bull Identify sequence followed in the CSSD

bull Identify categories of critical and noncritical items

WHY NEEDED

bull Microorganisms are ubiquitous

bull Since they cause contamination infection and decay it becomes necessary to remove or destroy them from materials or from areas

bull This is the object of sterilization

The process of sterilization is used

bull in microbiology for preventing contamination by extraneous organisms

bull in surgery for maintaining asepsis

bull in food and drug manufacture for ensuring safety from contaminating organisms and

bull in many other situations

The methods of sterilization employed depend on

bull the purpose for which it is carried out

bull the material which has to be sterilized and

bull the nature of the microorganisms that are to be removed or destroyed

Definition of termsbull Cleaning - the physical removal of organic

material or soil from objects is usually done by using water with or without detergents

bull Sterilization is the destruction of all forms of microbial life it is carried out in the hospital with steam under pressure liquid or gaseous chemicals or dry heat

bull Disinfection defined as the intermediate measures between physical cleaning and sterilization is carried out with pasteurization or chemical germicides

FUNCTIONS amp ACTIVITIES of CSSD

CSSD

Rinsing

cleaning

Drying

checking

sterilizationLabelling

Storage

Issue amp Distribution

Receipt

Various Agents In Sterilization

PHYSICAL AGENTS CHEMICAL AGENTS

SunlightAlcohols

Ethanol isopropyl

DryingAldehydes

Formaldehyde Glutaraldehyde

Dry heat

Hot air oven Incineration FlamingDyes

Moist heat

Boiling Pasteurization tyndallisation

Autoclaving

Halogens

Filtration Phenolic compounds

Radiation

Ionizing Non Ionizing

Gases

Ethylene oxide Formaldehyde beta

propiolactone(BPL)

Ultrasonic vibration Metallic salts and surface active agents

Physical Agents

SunlightbullDirect sunlight is a natural method of sterilization of water in tanks rivers and

lakes

bullDirect sunlight has an active germicidal effect due to the combined effect of

ultraviolet and heat rays

Dryingbull45 of the bacterial weight is due to water

bullTherefore drying in air has deleterious effect on many bacteria

bullThis is unreliable method spores are unaffected by drying

Dry heatFlaming

Inoculating loop or wire the tip of forceps are held in a Bunsen flame till they

become red hot

Incineration

This method is used to destroy contaminated cloth animal carcasses and pathological materials

Physical Agents cont

Hot air oven

This method is applicable to metals glassware and some heat-

resistant oils and waxes that are immiscible in water

Conditions

171ordmc for at least one hour

160ordmc for at least two hour

121ordmc for at least sixteen hour

Moist Heat

Flash autoclaves use 134degC for 3 minutes

Method Uses Comments

Water lt 100degc (Pasteurization) For sterilization of serum vaccines and body fluids

62degc for 15 min72degc for 30 secSpores are not destroyed

Water at 100degc For sterilization of glasswares metal and rubber items

Some spores are not destroyed

Arnold steamerStream at atmospheric pressure

For sterilization of culture media containing gelatin and sugar

Preserves properties of media

Autoclave Steam above atm pressure

For sterilization of culture media and laboratory materials

121degc at 15 psi for 15-20 minutesAlmost Kills all the bacteria and spores

Physical Agents cont

Filteration

Filtration helps to remove bacteria from large volumes of

fluid especially fluid containing heat-labile components such as

sera solution of sugars and antibiotics

A pore size of 02 m is effective because filters act not only

mechanically but by electrostatic adsorption of particles to their surface

Physical Agents cont

RADIATION

Non Ionisizing radiation

Types Produced by Mode of action Uses Comments

Low energy

(Infrared and

ultraviolet rays)

UV lamps DNA damage Infrared rays

Sterilization of prepacked

items such as syringes

and catheters

Ultraviolet rays

Used for disinfecting

operation threatres and

laboratories

Use of UV light

is limited by

penetration and

hazardous

Ionisizing radiation

High energy

ionizing type

(Gamma rays and

high energy

electrons such as

X-rays and

cosmic rays)

Cobalt-60

based

instruments

DNA damage For the sterilization of

antibiotics hormones

and other prepacked

disposable items such

as catheters gloves

syringes infusion sets

oils animal feeds etc

They are

expensive

They are very

effective due to

high penetrative

power

Physical Agents cont

Ultrasonic and sonic vibration

They have the property to disrupt the cells but the results have been variable

Gram negative rods are more sensitive to ultrasonic vibration whereas Gram

positive cocci spores of fungi and bacteria are resistant to the vibration

Ultrasonic devices are used in dental

However most sonic machines are not reliable for routine use

Chemical Agents cont

Properties of Ideal antiseptics or disinfectants should

Effective against all microorganisms and have a wide spectrum of

activity

Have speedy action

Be effective in presence of organic matter

Be effective in varying pH(acidic and alkaline medium)

Be stable

Also compatible with other antiseptics and disinfectants

Have high penetrating power

Not corrode metals

Not cause local irritation or sensitization

Not interfere with healing

Not be toxic if absorbed into circulationBe cheap and safe

The level of disinfection achieved depends on several factors

bull contact time

bull temperature

bull type and concentration of the active ingredients of the chemical germicide

bull the nature of the microbial contamination

Mechanisms of action of antiseptic and disinfectants

bull Oxidation of bacterial protoplasm

ndash Potassium permagnate H202 Halogens

bull Co-agulation (denaturation) of bacterial proteins amp disrupt cell membrane

ndash Phenols chlorhexidine alcohols aldehydes

bull Detergent like action uarr permeability of bacterial cell membrane

ndash Cetrimide soaps

Types of disinfectionbull High-level disinfection can be expected to

destroy all microorganisms with the exception of large numbers of bacterial spores

bull Intermediate disinfection inactivates Mycobacterium tuberculosis vegetative bacteria most viruses and most fungi does not necessarily kill bacterial spores

bull Low-level disinfection can kill most bacteria some viruses and some fungi cannot be relied on to kill resistant microorganisms such as tubercle bacilli or bacterial spores

Medical devices equipment and surgical materials are divided into three general categories based on the potential risk of

infection involved in their use

critical items

semicritical items

noncritical items

Critical items

bull Critical items are instruments or objects that are introduced directly into the bloodstream or into other normally sterile areas of the body

Examples of critical items are surgical instruments cardiac catheters implants pertinent components of the heart-lung oxygenator and the blood compartment of a hemodialyzer

Sterility at the time of use is required for these items consequently one of several accepted sterilization procedures is generally recommended

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Sterilization and Disinfection

Dr Nadir Mehmood

Asstt Prof of Surgery

RMC

Learning ObjectivesAt the end of the discussion a student will be able to

bull Define terms in relation to topic

bull Classify methods of sterilization and disinfectives

bull Enumerate the merits of different methods

bull Indicate the choice of method for different instruments and procedures

bull Identify sequence followed in the CSSD

bull Identify categories of critical and noncritical items

WHY NEEDED

bull Microorganisms are ubiquitous

bull Since they cause contamination infection and decay it becomes necessary to remove or destroy them from materials or from areas

bull This is the object of sterilization

The process of sterilization is used

bull in microbiology for preventing contamination by extraneous organisms

bull in surgery for maintaining asepsis

bull in food and drug manufacture for ensuring safety from contaminating organisms and

bull in many other situations

The methods of sterilization employed depend on

bull the purpose for which it is carried out

bull the material which has to be sterilized and

bull the nature of the microorganisms that are to be removed or destroyed

Definition of termsbull Cleaning - the physical removal of organic

material or soil from objects is usually done by using water with or without detergents

bull Sterilization is the destruction of all forms of microbial life it is carried out in the hospital with steam under pressure liquid or gaseous chemicals or dry heat

bull Disinfection defined as the intermediate measures between physical cleaning and sterilization is carried out with pasteurization or chemical germicides

FUNCTIONS amp ACTIVITIES of CSSD

CSSD

Rinsing

cleaning

Drying

checking

sterilizationLabelling

Storage

Issue amp Distribution

Receipt

Various Agents In Sterilization

PHYSICAL AGENTS CHEMICAL AGENTS

SunlightAlcohols

Ethanol isopropyl

DryingAldehydes

Formaldehyde Glutaraldehyde

Dry heat

Hot air oven Incineration FlamingDyes

Moist heat

Boiling Pasteurization tyndallisation

Autoclaving

Halogens

Filtration Phenolic compounds

Radiation

Ionizing Non Ionizing

Gases

Ethylene oxide Formaldehyde beta

propiolactone(BPL)

Ultrasonic vibration Metallic salts and surface active agents

Physical Agents

SunlightbullDirect sunlight is a natural method of sterilization of water in tanks rivers and

lakes

bullDirect sunlight has an active germicidal effect due to the combined effect of

ultraviolet and heat rays

Dryingbull45 of the bacterial weight is due to water

bullTherefore drying in air has deleterious effect on many bacteria

bullThis is unreliable method spores are unaffected by drying

Dry heatFlaming

Inoculating loop or wire the tip of forceps are held in a Bunsen flame till they

become red hot

Incineration

This method is used to destroy contaminated cloth animal carcasses and pathological materials

Physical Agents cont

Hot air oven

This method is applicable to metals glassware and some heat-

resistant oils and waxes that are immiscible in water

Conditions

171ordmc for at least one hour

160ordmc for at least two hour

121ordmc for at least sixteen hour

Moist Heat

Flash autoclaves use 134degC for 3 minutes

Method Uses Comments

Water lt 100degc (Pasteurization) For sterilization of serum vaccines and body fluids

62degc for 15 min72degc for 30 secSpores are not destroyed

Water at 100degc For sterilization of glasswares metal and rubber items

Some spores are not destroyed

Arnold steamerStream at atmospheric pressure

For sterilization of culture media containing gelatin and sugar

Preserves properties of media

Autoclave Steam above atm pressure

For sterilization of culture media and laboratory materials

121degc at 15 psi for 15-20 minutesAlmost Kills all the bacteria and spores

Physical Agents cont

Filteration

Filtration helps to remove bacteria from large volumes of

fluid especially fluid containing heat-labile components such as

sera solution of sugars and antibiotics

A pore size of 02 m is effective because filters act not only

mechanically but by electrostatic adsorption of particles to their surface

Physical Agents cont

RADIATION

Non Ionisizing radiation

Types Produced by Mode of action Uses Comments

Low energy

(Infrared and

ultraviolet rays)

UV lamps DNA damage Infrared rays

Sterilization of prepacked

items such as syringes

and catheters

Ultraviolet rays

Used for disinfecting

operation threatres and

laboratories

Use of UV light

is limited by

penetration and

hazardous

Ionisizing radiation

High energy

ionizing type

(Gamma rays and

high energy

electrons such as

X-rays and

cosmic rays)

Cobalt-60

based

instruments

DNA damage For the sterilization of

antibiotics hormones

and other prepacked

disposable items such

as catheters gloves

syringes infusion sets

oils animal feeds etc

They are

expensive

They are very

effective due to

high penetrative

power

Physical Agents cont

Ultrasonic and sonic vibration

They have the property to disrupt the cells but the results have been variable

Gram negative rods are more sensitive to ultrasonic vibration whereas Gram

positive cocci spores of fungi and bacteria are resistant to the vibration

Ultrasonic devices are used in dental

However most sonic machines are not reliable for routine use

Chemical Agents cont

Properties of Ideal antiseptics or disinfectants should

Effective against all microorganisms and have a wide spectrum of

activity

Have speedy action

Be effective in presence of organic matter

Be effective in varying pH(acidic and alkaline medium)

Be stable

Also compatible with other antiseptics and disinfectants

Have high penetrating power

Not corrode metals

Not cause local irritation or sensitization

Not interfere with healing

Not be toxic if absorbed into circulationBe cheap and safe

The level of disinfection achieved depends on several factors

bull contact time

bull temperature

bull type and concentration of the active ingredients of the chemical germicide

bull the nature of the microbial contamination

Mechanisms of action of antiseptic and disinfectants

bull Oxidation of bacterial protoplasm

ndash Potassium permagnate H202 Halogens

bull Co-agulation (denaturation) of bacterial proteins amp disrupt cell membrane

ndash Phenols chlorhexidine alcohols aldehydes

bull Detergent like action uarr permeability of bacterial cell membrane

ndash Cetrimide soaps

Types of disinfectionbull High-level disinfection can be expected to

destroy all microorganisms with the exception of large numbers of bacterial spores

bull Intermediate disinfection inactivates Mycobacterium tuberculosis vegetative bacteria most viruses and most fungi does not necessarily kill bacterial spores

bull Low-level disinfection can kill most bacteria some viruses and some fungi cannot be relied on to kill resistant microorganisms such as tubercle bacilli or bacterial spores

Medical devices equipment and surgical materials are divided into three general categories based on the potential risk of

infection involved in their use

critical items

semicritical items

noncritical items

Critical items

bull Critical items are instruments or objects that are introduced directly into the bloodstream or into other normally sterile areas of the body

Examples of critical items are surgical instruments cardiac catheters implants pertinent components of the heart-lung oxygenator and the blood compartment of a hemodialyzer

Sterility at the time of use is required for these items consequently one of several accepted sterilization procedures is generally recommended

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Learning ObjectivesAt the end of the discussion a student will be able to

bull Define terms in relation to topic

bull Classify methods of sterilization and disinfectives

bull Enumerate the merits of different methods

bull Indicate the choice of method for different instruments and procedures

bull Identify sequence followed in the CSSD

bull Identify categories of critical and noncritical items

WHY NEEDED

bull Microorganisms are ubiquitous

bull Since they cause contamination infection and decay it becomes necessary to remove or destroy them from materials or from areas

bull This is the object of sterilization

The process of sterilization is used

bull in microbiology for preventing contamination by extraneous organisms

bull in surgery for maintaining asepsis

bull in food and drug manufacture for ensuring safety from contaminating organisms and

bull in many other situations

The methods of sterilization employed depend on

bull the purpose for which it is carried out

bull the material which has to be sterilized and

bull the nature of the microorganisms that are to be removed or destroyed

Definition of termsbull Cleaning - the physical removal of organic

material or soil from objects is usually done by using water with or without detergents

bull Sterilization is the destruction of all forms of microbial life it is carried out in the hospital with steam under pressure liquid or gaseous chemicals or dry heat

bull Disinfection defined as the intermediate measures between physical cleaning and sterilization is carried out with pasteurization or chemical germicides

FUNCTIONS amp ACTIVITIES of CSSD

CSSD

Rinsing

cleaning

Drying

checking

sterilizationLabelling

Storage

Issue amp Distribution

Receipt

Various Agents In Sterilization

PHYSICAL AGENTS CHEMICAL AGENTS

SunlightAlcohols

Ethanol isopropyl

DryingAldehydes

Formaldehyde Glutaraldehyde

Dry heat

Hot air oven Incineration FlamingDyes

Moist heat

Boiling Pasteurization tyndallisation

Autoclaving

Halogens

Filtration Phenolic compounds

Radiation

Ionizing Non Ionizing

Gases

Ethylene oxide Formaldehyde beta

propiolactone(BPL)

Ultrasonic vibration Metallic salts and surface active agents

Physical Agents

SunlightbullDirect sunlight is a natural method of sterilization of water in tanks rivers and

lakes

bullDirect sunlight has an active germicidal effect due to the combined effect of

ultraviolet and heat rays

Dryingbull45 of the bacterial weight is due to water

bullTherefore drying in air has deleterious effect on many bacteria

bullThis is unreliable method spores are unaffected by drying

Dry heatFlaming

Inoculating loop or wire the tip of forceps are held in a Bunsen flame till they

become red hot

Incineration

This method is used to destroy contaminated cloth animal carcasses and pathological materials

Physical Agents cont

Hot air oven

This method is applicable to metals glassware and some heat-

resistant oils and waxes that are immiscible in water

Conditions

171ordmc for at least one hour

160ordmc for at least two hour

121ordmc for at least sixteen hour

Moist Heat

Flash autoclaves use 134degC for 3 minutes

Method Uses Comments

Water lt 100degc (Pasteurization) For sterilization of serum vaccines and body fluids

62degc for 15 min72degc for 30 secSpores are not destroyed

Water at 100degc For sterilization of glasswares metal and rubber items

Some spores are not destroyed

Arnold steamerStream at atmospheric pressure

For sterilization of culture media containing gelatin and sugar

Preserves properties of media

Autoclave Steam above atm pressure

For sterilization of culture media and laboratory materials

121degc at 15 psi for 15-20 minutesAlmost Kills all the bacteria and spores

Physical Agents cont

Filteration

Filtration helps to remove bacteria from large volumes of

fluid especially fluid containing heat-labile components such as

sera solution of sugars and antibiotics

A pore size of 02 m is effective because filters act not only

mechanically but by electrostatic adsorption of particles to their surface

Physical Agents cont

RADIATION

Non Ionisizing radiation

Types Produced by Mode of action Uses Comments

Low energy

(Infrared and

ultraviolet rays)

UV lamps DNA damage Infrared rays

Sterilization of prepacked

items such as syringes

and catheters

Ultraviolet rays

Used for disinfecting

operation threatres and

laboratories

Use of UV light

is limited by

penetration and

hazardous

Ionisizing radiation

High energy

ionizing type

(Gamma rays and

high energy

electrons such as

X-rays and

cosmic rays)

Cobalt-60

based

instruments

DNA damage For the sterilization of

antibiotics hormones

and other prepacked

disposable items such

as catheters gloves

syringes infusion sets

oils animal feeds etc

They are

expensive

They are very

effective due to

high penetrative

power

Physical Agents cont

Ultrasonic and sonic vibration

They have the property to disrupt the cells but the results have been variable

Gram negative rods are more sensitive to ultrasonic vibration whereas Gram

positive cocci spores of fungi and bacteria are resistant to the vibration

Ultrasonic devices are used in dental

However most sonic machines are not reliable for routine use

Chemical Agents cont

Properties of Ideal antiseptics or disinfectants should

Effective against all microorganisms and have a wide spectrum of

activity

Have speedy action

Be effective in presence of organic matter

Be effective in varying pH(acidic and alkaline medium)

Be stable

Also compatible with other antiseptics and disinfectants

Have high penetrating power

Not corrode metals

Not cause local irritation or sensitization

Not interfere with healing

Not be toxic if absorbed into circulationBe cheap and safe

The level of disinfection achieved depends on several factors

bull contact time

bull temperature

bull type and concentration of the active ingredients of the chemical germicide

bull the nature of the microbial contamination

Mechanisms of action of antiseptic and disinfectants

bull Oxidation of bacterial protoplasm

ndash Potassium permagnate H202 Halogens

bull Co-agulation (denaturation) of bacterial proteins amp disrupt cell membrane

ndash Phenols chlorhexidine alcohols aldehydes

bull Detergent like action uarr permeability of bacterial cell membrane

ndash Cetrimide soaps

Types of disinfectionbull High-level disinfection can be expected to

destroy all microorganisms with the exception of large numbers of bacterial spores

bull Intermediate disinfection inactivates Mycobacterium tuberculosis vegetative bacteria most viruses and most fungi does not necessarily kill bacterial spores

bull Low-level disinfection can kill most bacteria some viruses and some fungi cannot be relied on to kill resistant microorganisms such as tubercle bacilli or bacterial spores

Medical devices equipment and surgical materials are divided into three general categories based on the potential risk of

infection involved in their use

critical items

semicritical items

noncritical items

Critical items

bull Critical items are instruments or objects that are introduced directly into the bloodstream or into other normally sterile areas of the body

Examples of critical items are surgical instruments cardiac catheters implants pertinent components of the heart-lung oxygenator and the blood compartment of a hemodialyzer

Sterility at the time of use is required for these items consequently one of several accepted sterilization procedures is generally recommended

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

WHY NEEDED

bull Microorganisms are ubiquitous

bull Since they cause contamination infection and decay it becomes necessary to remove or destroy them from materials or from areas

bull This is the object of sterilization

The process of sterilization is used

bull in microbiology for preventing contamination by extraneous organisms

bull in surgery for maintaining asepsis

bull in food and drug manufacture for ensuring safety from contaminating organisms and

bull in many other situations

The methods of sterilization employed depend on

bull the purpose for which it is carried out

bull the material which has to be sterilized and

bull the nature of the microorganisms that are to be removed or destroyed

Definition of termsbull Cleaning - the physical removal of organic

material or soil from objects is usually done by using water with or without detergents

bull Sterilization is the destruction of all forms of microbial life it is carried out in the hospital with steam under pressure liquid or gaseous chemicals or dry heat

bull Disinfection defined as the intermediate measures between physical cleaning and sterilization is carried out with pasteurization or chemical germicides

FUNCTIONS amp ACTIVITIES of CSSD

CSSD

Rinsing

cleaning

Drying

checking

sterilizationLabelling

Storage

Issue amp Distribution

Receipt

Various Agents In Sterilization

PHYSICAL AGENTS CHEMICAL AGENTS

SunlightAlcohols

Ethanol isopropyl

DryingAldehydes

Formaldehyde Glutaraldehyde

Dry heat

Hot air oven Incineration FlamingDyes

Moist heat

Boiling Pasteurization tyndallisation

Autoclaving

Halogens

Filtration Phenolic compounds

Radiation

Ionizing Non Ionizing

Gases

Ethylene oxide Formaldehyde beta

propiolactone(BPL)

Ultrasonic vibration Metallic salts and surface active agents

Physical Agents

SunlightbullDirect sunlight is a natural method of sterilization of water in tanks rivers and

lakes

bullDirect sunlight has an active germicidal effect due to the combined effect of

ultraviolet and heat rays

Dryingbull45 of the bacterial weight is due to water

bullTherefore drying in air has deleterious effect on many bacteria

bullThis is unreliable method spores are unaffected by drying

Dry heatFlaming

Inoculating loop or wire the tip of forceps are held in a Bunsen flame till they

become red hot

Incineration

This method is used to destroy contaminated cloth animal carcasses and pathological materials

Physical Agents cont

Hot air oven

This method is applicable to metals glassware and some heat-

resistant oils and waxes that are immiscible in water

Conditions

171ordmc for at least one hour

160ordmc for at least two hour

121ordmc for at least sixteen hour

Moist Heat

Flash autoclaves use 134degC for 3 minutes

Method Uses Comments

Water lt 100degc (Pasteurization) For sterilization of serum vaccines and body fluids

62degc for 15 min72degc for 30 secSpores are not destroyed

Water at 100degc For sterilization of glasswares metal and rubber items

Some spores are not destroyed

Arnold steamerStream at atmospheric pressure

For sterilization of culture media containing gelatin and sugar

Preserves properties of media

Autoclave Steam above atm pressure

For sterilization of culture media and laboratory materials

121degc at 15 psi for 15-20 minutesAlmost Kills all the bacteria and spores

Physical Agents cont

Filteration

Filtration helps to remove bacteria from large volumes of

fluid especially fluid containing heat-labile components such as

sera solution of sugars and antibiotics

A pore size of 02 m is effective because filters act not only

mechanically but by electrostatic adsorption of particles to their surface

Physical Agents cont

RADIATION

Non Ionisizing radiation

Types Produced by Mode of action Uses Comments

Low energy

(Infrared and

ultraviolet rays)

UV lamps DNA damage Infrared rays

Sterilization of prepacked

items such as syringes

and catheters

Ultraviolet rays

Used for disinfecting

operation threatres and

laboratories

Use of UV light

is limited by

penetration and

hazardous

Ionisizing radiation

High energy

ionizing type

(Gamma rays and

high energy

electrons such as

X-rays and

cosmic rays)

Cobalt-60

based

instruments

DNA damage For the sterilization of

antibiotics hormones

and other prepacked

disposable items such

as catheters gloves

syringes infusion sets

oils animal feeds etc

They are

expensive

They are very

effective due to

high penetrative

power

Physical Agents cont

Ultrasonic and sonic vibration

They have the property to disrupt the cells but the results have been variable

Gram negative rods are more sensitive to ultrasonic vibration whereas Gram

positive cocci spores of fungi and bacteria are resistant to the vibration

Ultrasonic devices are used in dental

However most sonic machines are not reliable for routine use

Chemical Agents cont

Properties of Ideal antiseptics or disinfectants should

Effective against all microorganisms and have a wide spectrum of

activity

Have speedy action

Be effective in presence of organic matter

Be effective in varying pH(acidic and alkaline medium)

Be stable

Also compatible with other antiseptics and disinfectants

Have high penetrating power

Not corrode metals

Not cause local irritation or sensitization

Not interfere with healing

Not be toxic if absorbed into circulationBe cheap and safe

The level of disinfection achieved depends on several factors

bull contact time

bull temperature

bull type and concentration of the active ingredients of the chemical germicide

bull the nature of the microbial contamination

Mechanisms of action of antiseptic and disinfectants

bull Oxidation of bacterial protoplasm

ndash Potassium permagnate H202 Halogens

bull Co-agulation (denaturation) of bacterial proteins amp disrupt cell membrane

ndash Phenols chlorhexidine alcohols aldehydes

bull Detergent like action uarr permeability of bacterial cell membrane

ndash Cetrimide soaps

Types of disinfectionbull High-level disinfection can be expected to

destroy all microorganisms with the exception of large numbers of bacterial spores

bull Intermediate disinfection inactivates Mycobacterium tuberculosis vegetative bacteria most viruses and most fungi does not necessarily kill bacterial spores

bull Low-level disinfection can kill most bacteria some viruses and some fungi cannot be relied on to kill resistant microorganisms such as tubercle bacilli or bacterial spores

Medical devices equipment and surgical materials are divided into three general categories based on the potential risk of

infection involved in their use

critical items

semicritical items

noncritical items

Critical items

bull Critical items are instruments or objects that are introduced directly into the bloodstream or into other normally sterile areas of the body

Examples of critical items are surgical instruments cardiac catheters implants pertinent components of the heart-lung oxygenator and the blood compartment of a hemodialyzer

Sterility at the time of use is required for these items consequently one of several accepted sterilization procedures is generally recommended

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

The process of sterilization is used

bull in microbiology for preventing contamination by extraneous organisms

bull in surgery for maintaining asepsis

bull in food and drug manufacture for ensuring safety from contaminating organisms and

bull in many other situations

The methods of sterilization employed depend on

bull the purpose for which it is carried out

bull the material which has to be sterilized and

bull the nature of the microorganisms that are to be removed or destroyed

Definition of termsbull Cleaning - the physical removal of organic

material or soil from objects is usually done by using water with or without detergents

bull Sterilization is the destruction of all forms of microbial life it is carried out in the hospital with steam under pressure liquid or gaseous chemicals or dry heat

bull Disinfection defined as the intermediate measures between physical cleaning and sterilization is carried out with pasteurization or chemical germicides

FUNCTIONS amp ACTIVITIES of CSSD

CSSD

Rinsing

cleaning

Drying

checking

sterilizationLabelling

Storage

Issue amp Distribution

Receipt

Various Agents In Sterilization

PHYSICAL AGENTS CHEMICAL AGENTS

SunlightAlcohols

Ethanol isopropyl

DryingAldehydes

Formaldehyde Glutaraldehyde

Dry heat

Hot air oven Incineration FlamingDyes

Moist heat

Boiling Pasteurization tyndallisation

Autoclaving

Halogens

Filtration Phenolic compounds

Radiation

Ionizing Non Ionizing

Gases

Ethylene oxide Formaldehyde beta

propiolactone(BPL)

Ultrasonic vibration Metallic salts and surface active agents

Physical Agents

SunlightbullDirect sunlight is a natural method of sterilization of water in tanks rivers and

lakes

bullDirect sunlight has an active germicidal effect due to the combined effect of

ultraviolet and heat rays

Dryingbull45 of the bacterial weight is due to water

bullTherefore drying in air has deleterious effect on many bacteria

bullThis is unreliable method spores are unaffected by drying

Dry heatFlaming

Inoculating loop or wire the tip of forceps are held in a Bunsen flame till they

become red hot

Incineration

This method is used to destroy contaminated cloth animal carcasses and pathological materials

Physical Agents cont

Hot air oven

This method is applicable to metals glassware and some heat-

resistant oils and waxes that are immiscible in water

Conditions

171ordmc for at least one hour

160ordmc for at least two hour

121ordmc for at least sixteen hour

Moist Heat

Flash autoclaves use 134degC for 3 minutes

Method Uses Comments

Water lt 100degc (Pasteurization) For sterilization of serum vaccines and body fluids

62degc for 15 min72degc for 30 secSpores are not destroyed

Water at 100degc For sterilization of glasswares metal and rubber items

Some spores are not destroyed

Arnold steamerStream at atmospheric pressure

For sterilization of culture media containing gelatin and sugar

Preserves properties of media

Autoclave Steam above atm pressure

For sterilization of culture media and laboratory materials

121degc at 15 psi for 15-20 minutesAlmost Kills all the bacteria and spores

Physical Agents cont

Filteration

Filtration helps to remove bacteria from large volumes of

fluid especially fluid containing heat-labile components such as

sera solution of sugars and antibiotics

A pore size of 02 m is effective because filters act not only

mechanically but by electrostatic adsorption of particles to their surface

Physical Agents cont

RADIATION

Non Ionisizing radiation

Types Produced by Mode of action Uses Comments

Low energy

(Infrared and

ultraviolet rays)

UV lamps DNA damage Infrared rays

Sterilization of prepacked

items such as syringes

and catheters

Ultraviolet rays

Used for disinfecting

operation threatres and

laboratories

Use of UV light

is limited by

penetration and

hazardous

Ionisizing radiation

High energy

ionizing type

(Gamma rays and

high energy

electrons such as

X-rays and

cosmic rays)

Cobalt-60

based

instruments

DNA damage For the sterilization of

antibiotics hormones

and other prepacked

disposable items such

as catheters gloves

syringes infusion sets

oils animal feeds etc

They are

expensive

They are very

effective due to

high penetrative

power

Physical Agents cont

Ultrasonic and sonic vibration

They have the property to disrupt the cells but the results have been variable

Gram negative rods are more sensitive to ultrasonic vibration whereas Gram

positive cocci spores of fungi and bacteria are resistant to the vibration

Ultrasonic devices are used in dental

However most sonic machines are not reliable for routine use

Chemical Agents cont

Properties of Ideal antiseptics or disinfectants should

Effective against all microorganisms and have a wide spectrum of

activity

Have speedy action

Be effective in presence of organic matter

Be effective in varying pH(acidic and alkaline medium)

Be stable

Also compatible with other antiseptics and disinfectants

Have high penetrating power

Not corrode metals

Not cause local irritation or sensitization

Not interfere with healing

Not be toxic if absorbed into circulationBe cheap and safe

The level of disinfection achieved depends on several factors

bull contact time

bull temperature

bull type and concentration of the active ingredients of the chemical germicide

bull the nature of the microbial contamination

Mechanisms of action of antiseptic and disinfectants

bull Oxidation of bacterial protoplasm

ndash Potassium permagnate H202 Halogens

bull Co-agulation (denaturation) of bacterial proteins amp disrupt cell membrane

ndash Phenols chlorhexidine alcohols aldehydes

bull Detergent like action uarr permeability of bacterial cell membrane

ndash Cetrimide soaps

Types of disinfectionbull High-level disinfection can be expected to

destroy all microorganisms with the exception of large numbers of bacterial spores

bull Intermediate disinfection inactivates Mycobacterium tuberculosis vegetative bacteria most viruses and most fungi does not necessarily kill bacterial spores

bull Low-level disinfection can kill most bacteria some viruses and some fungi cannot be relied on to kill resistant microorganisms such as tubercle bacilli or bacterial spores

Medical devices equipment and surgical materials are divided into three general categories based on the potential risk of

infection involved in their use

critical items

semicritical items

noncritical items

Critical items

bull Critical items are instruments or objects that are introduced directly into the bloodstream or into other normally sterile areas of the body

Examples of critical items are surgical instruments cardiac catheters implants pertinent components of the heart-lung oxygenator and the blood compartment of a hemodialyzer

Sterility at the time of use is required for these items consequently one of several accepted sterilization procedures is generally recommended

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Definition of termsbull Cleaning - the physical removal of organic

material or soil from objects is usually done by using water with or without detergents

bull Sterilization is the destruction of all forms of microbial life it is carried out in the hospital with steam under pressure liquid or gaseous chemicals or dry heat

bull Disinfection defined as the intermediate measures between physical cleaning and sterilization is carried out with pasteurization or chemical germicides

FUNCTIONS amp ACTIVITIES of CSSD

CSSD

Rinsing

cleaning

Drying

checking

sterilizationLabelling

Storage

Issue amp Distribution

Receipt

Various Agents In Sterilization

PHYSICAL AGENTS CHEMICAL AGENTS

SunlightAlcohols

Ethanol isopropyl

DryingAldehydes

Formaldehyde Glutaraldehyde

Dry heat

Hot air oven Incineration FlamingDyes

Moist heat

Boiling Pasteurization tyndallisation

Autoclaving

Halogens

Filtration Phenolic compounds

Radiation

Ionizing Non Ionizing

Gases

Ethylene oxide Formaldehyde beta

propiolactone(BPL)

Ultrasonic vibration Metallic salts and surface active agents

Physical Agents

SunlightbullDirect sunlight is a natural method of sterilization of water in tanks rivers and

lakes

bullDirect sunlight has an active germicidal effect due to the combined effect of

ultraviolet and heat rays

Dryingbull45 of the bacterial weight is due to water

bullTherefore drying in air has deleterious effect on many bacteria

bullThis is unreliable method spores are unaffected by drying

Dry heatFlaming

Inoculating loop or wire the tip of forceps are held in a Bunsen flame till they

become red hot

Incineration

This method is used to destroy contaminated cloth animal carcasses and pathological materials

Physical Agents cont

Hot air oven

This method is applicable to metals glassware and some heat-

resistant oils and waxes that are immiscible in water

Conditions

171ordmc for at least one hour

160ordmc for at least two hour

121ordmc for at least sixteen hour

Moist Heat

Flash autoclaves use 134degC for 3 minutes

Method Uses Comments

Water lt 100degc (Pasteurization) For sterilization of serum vaccines and body fluids

62degc for 15 min72degc for 30 secSpores are not destroyed

Water at 100degc For sterilization of glasswares metal and rubber items

Some spores are not destroyed

Arnold steamerStream at atmospheric pressure

For sterilization of culture media containing gelatin and sugar

Preserves properties of media

Autoclave Steam above atm pressure

For sterilization of culture media and laboratory materials

121degc at 15 psi for 15-20 minutesAlmost Kills all the bacteria and spores

Physical Agents cont

Filteration

Filtration helps to remove bacteria from large volumes of

fluid especially fluid containing heat-labile components such as

sera solution of sugars and antibiotics

A pore size of 02 m is effective because filters act not only

mechanically but by electrostatic adsorption of particles to their surface

Physical Agents cont

RADIATION

Non Ionisizing radiation

Types Produced by Mode of action Uses Comments

Low energy

(Infrared and

ultraviolet rays)

UV lamps DNA damage Infrared rays

Sterilization of prepacked

items such as syringes

and catheters

Ultraviolet rays

Used for disinfecting

operation threatres and

laboratories

Use of UV light

is limited by

penetration and

hazardous

Ionisizing radiation

High energy

ionizing type

(Gamma rays and

high energy

electrons such as

X-rays and

cosmic rays)

Cobalt-60

based

instruments

DNA damage For the sterilization of

antibiotics hormones

and other prepacked

disposable items such

as catheters gloves

syringes infusion sets

oils animal feeds etc

They are

expensive

They are very

effective due to

high penetrative

power

Physical Agents cont

Ultrasonic and sonic vibration

They have the property to disrupt the cells but the results have been variable

Gram negative rods are more sensitive to ultrasonic vibration whereas Gram

positive cocci spores of fungi and bacteria are resistant to the vibration

Ultrasonic devices are used in dental

However most sonic machines are not reliable for routine use

Chemical Agents cont

Properties of Ideal antiseptics or disinfectants should

Effective against all microorganisms and have a wide spectrum of

activity

Have speedy action

Be effective in presence of organic matter

Be effective in varying pH(acidic and alkaline medium)

Be stable

Also compatible with other antiseptics and disinfectants

Have high penetrating power

Not corrode metals

Not cause local irritation or sensitization

Not interfere with healing

Not be toxic if absorbed into circulationBe cheap and safe

The level of disinfection achieved depends on several factors

bull contact time

bull temperature

bull type and concentration of the active ingredients of the chemical germicide

bull the nature of the microbial contamination

Mechanisms of action of antiseptic and disinfectants

bull Oxidation of bacterial protoplasm

ndash Potassium permagnate H202 Halogens

bull Co-agulation (denaturation) of bacterial proteins amp disrupt cell membrane

ndash Phenols chlorhexidine alcohols aldehydes

bull Detergent like action uarr permeability of bacterial cell membrane

ndash Cetrimide soaps

Types of disinfectionbull High-level disinfection can be expected to

destroy all microorganisms with the exception of large numbers of bacterial spores

bull Intermediate disinfection inactivates Mycobacterium tuberculosis vegetative bacteria most viruses and most fungi does not necessarily kill bacterial spores

bull Low-level disinfection can kill most bacteria some viruses and some fungi cannot be relied on to kill resistant microorganisms such as tubercle bacilli or bacterial spores

Medical devices equipment and surgical materials are divided into three general categories based on the potential risk of

infection involved in their use

critical items

semicritical items

noncritical items

Critical items

bull Critical items are instruments or objects that are introduced directly into the bloodstream or into other normally sterile areas of the body

Examples of critical items are surgical instruments cardiac catheters implants pertinent components of the heart-lung oxygenator and the blood compartment of a hemodialyzer

Sterility at the time of use is required for these items consequently one of several accepted sterilization procedures is generally recommended

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

FUNCTIONS amp ACTIVITIES of CSSD

CSSD

Rinsing

cleaning

Drying

checking

sterilizationLabelling

Storage

Issue amp Distribution

Receipt

Various Agents In Sterilization

PHYSICAL AGENTS CHEMICAL AGENTS

SunlightAlcohols

Ethanol isopropyl

DryingAldehydes

Formaldehyde Glutaraldehyde

Dry heat

Hot air oven Incineration FlamingDyes

Moist heat

Boiling Pasteurization tyndallisation

Autoclaving

Halogens

Filtration Phenolic compounds

Radiation

Ionizing Non Ionizing

Gases

Ethylene oxide Formaldehyde beta

propiolactone(BPL)

Ultrasonic vibration Metallic salts and surface active agents

Physical Agents

SunlightbullDirect sunlight is a natural method of sterilization of water in tanks rivers and

lakes

bullDirect sunlight has an active germicidal effect due to the combined effect of

ultraviolet and heat rays

Dryingbull45 of the bacterial weight is due to water

bullTherefore drying in air has deleterious effect on many bacteria

bullThis is unreliable method spores are unaffected by drying

Dry heatFlaming

Inoculating loop or wire the tip of forceps are held in a Bunsen flame till they

become red hot

Incineration

This method is used to destroy contaminated cloth animal carcasses and pathological materials

Physical Agents cont

Hot air oven

This method is applicable to metals glassware and some heat-

resistant oils and waxes that are immiscible in water

Conditions

171ordmc for at least one hour

160ordmc for at least two hour

121ordmc for at least sixteen hour

Moist Heat

Flash autoclaves use 134degC for 3 minutes

Method Uses Comments

Water lt 100degc (Pasteurization) For sterilization of serum vaccines and body fluids

62degc for 15 min72degc for 30 secSpores are not destroyed

Water at 100degc For sterilization of glasswares metal and rubber items

Some spores are not destroyed

Arnold steamerStream at atmospheric pressure

For sterilization of culture media containing gelatin and sugar

Preserves properties of media

Autoclave Steam above atm pressure

For sterilization of culture media and laboratory materials

121degc at 15 psi for 15-20 minutesAlmost Kills all the bacteria and spores

Physical Agents cont

Filteration

Filtration helps to remove bacteria from large volumes of

fluid especially fluid containing heat-labile components such as

sera solution of sugars and antibiotics

A pore size of 02 m is effective because filters act not only

mechanically but by electrostatic adsorption of particles to their surface

Physical Agents cont

RADIATION

Non Ionisizing radiation

Types Produced by Mode of action Uses Comments

Low energy

(Infrared and

ultraviolet rays)

UV lamps DNA damage Infrared rays

Sterilization of prepacked

items such as syringes

and catheters

Ultraviolet rays

Used for disinfecting

operation threatres and

laboratories

Use of UV light

is limited by

penetration and

hazardous

Ionisizing radiation

High energy

ionizing type

(Gamma rays and

high energy

electrons such as

X-rays and

cosmic rays)

Cobalt-60

based

instruments

DNA damage For the sterilization of

antibiotics hormones

and other prepacked

disposable items such

as catheters gloves

syringes infusion sets

oils animal feeds etc

They are

expensive

They are very

effective due to

high penetrative

power

Physical Agents cont

Ultrasonic and sonic vibration

They have the property to disrupt the cells but the results have been variable

Gram negative rods are more sensitive to ultrasonic vibration whereas Gram

positive cocci spores of fungi and bacteria are resistant to the vibration

Ultrasonic devices are used in dental

However most sonic machines are not reliable for routine use

Chemical Agents cont

Properties of Ideal antiseptics or disinfectants should

Effective against all microorganisms and have a wide spectrum of

activity

Have speedy action

Be effective in presence of organic matter

Be effective in varying pH(acidic and alkaline medium)

Be stable

Also compatible with other antiseptics and disinfectants

Have high penetrating power

Not corrode metals

Not cause local irritation or sensitization

Not interfere with healing

Not be toxic if absorbed into circulationBe cheap and safe

The level of disinfection achieved depends on several factors

bull contact time

bull temperature

bull type and concentration of the active ingredients of the chemical germicide

bull the nature of the microbial contamination

Mechanisms of action of antiseptic and disinfectants

bull Oxidation of bacterial protoplasm

ndash Potassium permagnate H202 Halogens

bull Co-agulation (denaturation) of bacterial proteins amp disrupt cell membrane

ndash Phenols chlorhexidine alcohols aldehydes

bull Detergent like action uarr permeability of bacterial cell membrane

ndash Cetrimide soaps

Types of disinfectionbull High-level disinfection can be expected to

destroy all microorganisms with the exception of large numbers of bacterial spores

bull Intermediate disinfection inactivates Mycobacterium tuberculosis vegetative bacteria most viruses and most fungi does not necessarily kill bacterial spores

bull Low-level disinfection can kill most bacteria some viruses and some fungi cannot be relied on to kill resistant microorganisms such as tubercle bacilli or bacterial spores

Medical devices equipment and surgical materials are divided into three general categories based on the potential risk of

infection involved in their use

critical items

semicritical items

noncritical items

Critical items

bull Critical items are instruments or objects that are introduced directly into the bloodstream or into other normally sterile areas of the body

Examples of critical items are surgical instruments cardiac catheters implants pertinent components of the heart-lung oxygenator and the blood compartment of a hemodialyzer

Sterility at the time of use is required for these items consequently one of several accepted sterilization procedures is generally recommended

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Various Agents In Sterilization

PHYSICAL AGENTS CHEMICAL AGENTS

SunlightAlcohols

Ethanol isopropyl

DryingAldehydes

Formaldehyde Glutaraldehyde

Dry heat

Hot air oven Incineration FlamingDyes

Moist heat

Boiling Pasteurization tyndallisation

Autoclaving

Halogens

Filtration Phenolic compounds

Radiation

Ionizing Non Ionizing

Gases

Ethylene oxide Formaldehyde beta

propiolactone(BPL)

Ultrasonic vibration Metallic salts and surface active agents

Physical Agents

SunlightbullDirect sunlight is a natural method of sterilization of water in tanks rivers and

lakes

bullDirect sunlight has an active germicidal effect due to the combined effect of

ultraviolet and heat rays

Dryingbull45 of the bacterial weight is due to water

bullTherefore drying in air has deleterious effect on many bacteria

bullThis is unreliable method spores are unaffected by drying

Dry heatFlaming

Inoculating loop or wire the tip of forceps are held in a Bunsen flame till they

become red hot

Incineration

This method is used to destroy contaminated cloth animal carcasses and pathological materials

Physical Agents cont

Hot air oven

This method is applicable to metals glassware and some heat-

resistant oils and waxes that are immiscible in water

Conditions

171ordmc for at least one hour

160ordmc for at least two hour

121ordmc for at least sixteen hour

Moist Heat

Flash autoclaves use 134degC for 3 minutes

Method Uses Comments

Water lt 100degc (Pasteurization) For sterilization of serum vaccines and body fluids

62degc for 15 min72degc for 30 secSpores are not destroyed

Water at 100degc For sterilization of glasswares metal and rubber items

Some spores are not destroyed

Arnold steamerStream at atmospheric pressure

For sterilization of culture media containing gelatin and sugar

Preserves properties of media

Autoclave Steam above atm pressure

For sterilization of culture media and laboratory materials

121degc at 15 psi for 15-20 minutesAlmost Kills all the bacteria and spores

Physical Agents cont

Filteration

Filtration helps to remove bacteria from large volumes of

fluid especially fluid containing heat-labile components such as

sera solution of sugars and antibiotics

A pore size of 02 m is effective because filters act not only

mechanically but by electrostatic adsorption of particles to their surface

Physical Agents cont

RADIATION

Non Ionisizing radiation

Types Produced by Mode of action Uses Comments

Low energy

(Infrared and

ultraviolet rays)

UV lamps DNA damage Infrared rays

Sterilization of prepacked

items such as syringes

and catheters

Ultraviolet rays

Used for disinfecting

operation threatres and

laboratories

Use of UV light

is limited by

penetration and

hazardous

Ionisizing radiation

High energy

ionizing type

(Gamma rays and

high energy

electrons such as

X-rays and

cosmic rays)

Cobalt-60

based

instruments

DNA damage For the sterilization of

antibiotics hormones

and other prepacked

disposable items such

as catheters gloves

syringes infusion sets

oils animal feeds etc

They are

expensive

They are very

effective due to

high penetrative

power

Physical Agents cont

Ultrasonic and sonic vibration

They have the property to disrupt the cells but the results have been variable

Gram negative rods are more sensitive to ultrasonic vibration whereas Gram

positive cocci spores of fungi and bacteria are resistant to the vibration

Ultrasonic devices are used in dental

However most sonic machines are not reliable for routine use

Chemical Agents cont

Properties of Ideal antiseptics or disinfectants should

Effective against all microorganisms and have a wide spectrum of

activity

Have speedy action

Be effective in presence of organic matter

Be effective in varying pH(acidic and alkaline medium)

Be stable

Also compatible with other antiseptics and disinfectants

Have high penetrating power

Not corrode metals

Not cause local irritation or sensitization

Not interfere with healing

Not be toxic if absorbed into circulationBe cheap and safe

The level of disinfection achieved depends on several factors

bull contact time

bull temperature

bull type and concentration of the active ingredients of the chemical germicide

bull the nature of the microbial contamination

Mechanisms of action of antiseptic and disinfectants

bull Oxidation of bacterial protoplasm

ndash Potassium permagnate H202 Halogens

bull Co-agulation (denaturation) of bacterial proteins amp disrupt cell membrane

ndash Phenols chlorhexidine alcohols aldehydes

bull Detergent like action uarr permeability of bacterial cell membrane

ndash Cetrimide soaps

Types of disinfectionbull High-level disinfection can be expected to

destroy all microorganisms with the exception of large numbers of bacterial spores

bull Intermediate disinfection inactivates Mycobacterium tuberculosis vegetative bacteria most viruses and most fungi does not necessarily kill bacterial spores

bull Low-level disinfection can kill most bacteria some viruses and some fungi cannot be relied on to kill resistant microorganisms such as tubercle bacilli or bacterial spores

Medical devices equipment and surgical materials are divided into three general categories based on the potential risk of

infection involved in their use

critical items

semicritical items

noncritical items

Critical items

bull Critical items are instruments or objects that are introduced directly into the bloodstream or into other normally sterile areas of the body

Examples of critical items are surgical instruments cardiac catheters implants pertinent components of the heart-lung oxygenator and the blood compartment of a hemodialyzer

Sterility at the time of use is required for these items consequently one of several accepted sterilization procedures is generally recommended

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Physical Agents

SunlightbullDirect sunlight is a natural method of sterilization of water in tanks rivers and

lakes

bullDirect sunlight has an active germicidal effect due to the combined effect of

ultraviolet and heat rays

Dryingbull45 of the bacterial weight is due to water

bullTherefore drying in air has deleterious effect on many bacteria

bullThis is unreliable method spores are unaffected by drying

Dry heatFlaming

Inoculating loop or wire the tip of forceps are held in a Bunsen flame till they

become red hot

Incineration

This method is used to destroy contaminated cloth animal carcasses and pathological materials

Physical Agents cont

Hot air oven

This method is applicable to metals glassware and some heat-

resistant oils and waxes that are immiscible in water

Conditions

171ordmc for at least one hour

160ordmc for at least two hour

121ordmc for at least sixteen hour

Moist Heat

Flash autoclaves use 134degC for 3 minutes

Method Uses Comments

Water lt 100degc (Pasteurization) For sterilization of serum vaccines and body fluids

62degc for 15 min72degc for 30 secSpores are not destroyed

Water at 100degc For sterilization of glasswares metal and rubber items

Some spores are not destroyed

Arnold steamerStream at atmospheric pressure

For sterilization of culture media containing gelatin and sugar

Preserves properties of media

Autoclave Steam above atm pressure

For sterilization of culture media and laboratory materials

121degc at 15 psi for 15-20 minutesAlmost Kills all the bacteria and spores

Physical Agents cont

Filteration

Filtration helps to remove bacteria from large volumes of

fluid especially fluid containing heat-labile components such as

sera solution of sugars and antibiotics

A pore size of 02 m is effective because filters act not only

mechanically but by electrostatic adsorption of particles to their surface

Physical Agents cont

RADIATION

Non Ionisizing radiation

Types Produced by Mode of action Uses Comments

Low energy

(Infrared and

ultraviolet rays)

UV lamps DNA damage Infrared rays

Sterilization of prepacked

items such as syringes

and catheters

Ultraviolet rays

Used for disinfecting

operation threatres and

laboratories

Use of UV light

is limited by

penetration and

hazardous

Ionisizing radiation

High energy

ionizing type

(Gamma rays and

high energy

electrons such as

X-rays and

cosmic rays)

Cobalt-60

based

instruments

DNA damage For the sterilization of

antibiotics hormones

and other prepacked

disposable items such

as catheters gloves

syringes infusion sets

oils animal feeds etc

They are

expensive

They are very

effective due to

high penetrative

power

Physical Agents cont

Ultrasonic and sonic vibration

They have the property to disrupt the cells but the results have been variable

Gram negative rods are more sensitive to ultrasonic vibration whereas Gram

positive cocci spores of fungi and bacteria are resistant to the vibration

Ultrasonic devices are used in dental

However most sonic machines are not reliable for routine use

Chemical Agents cont

Properties of Ideal antiseptics or disinfectants should

Effective against all microorganisms and have a wide spectrum of

activity

Have speedy action

Be effective in presence of organic matter

Be effective in varying pH(acidic and alkaline medium)

Be stable

Also compatible with other antiseptics and disinfectants

Have high penetrating power

Not corrode metals

Not cause local irritation or sensitization

Not interfere with healing

Not be toxic if absorbed into circulationBe cheap and safe

The level of disinfection achieved depends on several factors

bull contact time

bull temperature

bull type and concentration of the active ingredients of the chemical germicide

bull the nature of the microbial contamination

Mechanisms of action of antiseptic and disinfectants

bull Oxidation of bacterial protoplasm

ndash Potassium permagnate H202 Halogens

bull Co-agulation (denaturation) of bacterial proteins amp disrupt cell membrane

ndash Phenols chlorhexidine alcohols aldehydes

bull Detergent like action uarr permeability of bacterial cell membrane

ndash Cetrimide soaps

Types of disinfectionbull High-level disinfection can be expected to

destroy all microorganisms with the exception of large numbers of bacterial spores

bull Intermediate disinfection inactivates Mycobacterium tuberculosis vegetative bacteria most viruses and most fungi does not necessarily kill bacterial spores

bull Low-level disinfection can kill most bacteria some viruses and some fungi cannot be relied on to kill resistant microorganisms such as tubercle bacilli or bacterial spores

Medical devices equipment and surgical materials are divided into three general categories based on the potential risk of

infection involved in their use

critical items

semicritical items

noncritical items

Critical items

bull Critical items are instruments or objects that are introduced directly into the bloodstream or into other normally sterile areas of the body

Examples of critical items are surgical instruments cardiac catheters implants pertinent components of the heart-lung oxygenator and the blood compartment of a hemodialyzer

Sterility at the time of use is required for these items consequently one of several accepted sterilization procedures is generally recommended

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Physical Agents cont

Hot air oven

This method is applicable to metals glassware and some heat-

resistant oils and waxes that are immiscible in water

Conditions

171ordmc for at least one hour

160ordmc for at least two hour

121ordmc for at least sixteen hour

Moist Heat

Flash autoclaves use 134degC for 3 minutes

Method Uses Comments

Water lt 100degc (Pasteurization) For sterilization of serum vaccines and body fluids

62degc for 15 min72degc for 30 secSpores are not destroyed

Water at 100degc For sterilization of glasswares metal and rubber items

Some spores are not destroyed

Arnold steamerStream at atmospheric pressure

For sterilization of culture media containing gelatin and sugar

Preserves properties of media

Autoclave Steam above atm pressure

For sterilization of culture media and laboratory materials

121degc at 15 psi for 15-20 minutesAlmost Kills all the bacteria and spores

Physical Agents cont

Filteration

Filtration helps to remove bacteria from large volumes of

fluid especially fluid containing heat-labile components such as

sera solution of sugars and antibiotics

A pore size of 02 m is effective because filters act not only

mechanically but by electrostatic adsorption of particles to their surface

Physical Agents cont

RADIATION

Non Ionisizing radiation

Types Produced by Mode of action Uses Comments

Low energy

(Infrared and

ultraviolet rays)

UV lamps DNA damage Infrared rays

Sterilization of prepacked

items such as syringes

and catheters

Ultraviolet rays

Used for disinfecting

operation threatres and

laboratories

Use of UV light

is limited by

penetration and

hazardous

Ionisizing radiation

High energy

ionizing type

(Gamma rays and

high energy

electrons such as

X-rays and

cosmic rays)

Cobalt-60

based

instruments

DNA damage For the sterilization of

antibiotics hormones

and other prepacked

disposable items such

as catheters gloves

syringes infusion sets

oils animal feeds etc

They are

expensive

They are very

effective due to

high penetrative

power

Physical Agents cont

Ultrasonic and sonic vibration

They have the property to disrupt the cells but the results have been variable

Gram negative rods are more sensitive to ultrasonic vibration whereas Gram

positive cocci spores of fungi and bacteria are resistant to the vibration

Ultrasonic devices are used in dental

However most sonic machines are not reliable for routine use

Chemical Agents cont

Properties of Ideal antiseptics or disinfectants should

Effective against all microorganisms and have a wide spectrum of

activity

Have speedy action

Be effective in presence of organic matter

Be effective in varying pH(acidic and alkaline medium)

Be stable

Also compatible with other antiseptics and disinfectants

Have high penetrating power

Not corrode metals

Not cause local irritation or sensitization

Not interfere with healing

Not be toxic if absorbed into circulationBe cheap and safe

The level of disinfection achieved depends on several factors

bull contact time

bull temperature

bull type and concentration of the active ingredients of the chemical germicide

bull the nature of the microbial contamination

Mechanisms of action of antiseptic and disinfectants

bull Oxidation of bacterial protoplasm

ndash Potassium permagnate H202 Halogens

bull Co-agulation (denaturation) of bacterial proteins amp disrupt cell membrane

ndash Phenols chlorhexidine alcohols aldehydes

bull Detergent like action uarr permeability of bacterial cell membrane

ndash Cetrimide soaps

Types of disinfectionbull High-level disinfection can be expected to

destroy all microorganisms with the exception of large numbers of bacterial spores

bull Intermediate disinfection inactivates Mycobacterium tuberculosis vegetative bacteria most viruses and most fungi does not necessarily kill bacterial spores

bull Low-level disinfection can kill most bacteria some viruses and some fungi cannot be relied on to kill resistant microorganisms such as tubercle bacilli or bacterial spores

Medical devices equipment and surgical materials are divided into three general categories based on the potential risk of

infection involved in their use

critical items

semicritical items

noncritical items

Critical items

bull Critical items are instruments or objects that are introduced directly into the bloodstream or into other normally sterile areas of the body

Examples of critical items are surgical instruments cardiac catheters implants pertinent components of the heart-lung oxygenator and the blood compartment of a hemodialyzer

Sterility at the time of use is required for these items consequently one of several accepted sterilization procedures is generally recommended

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Physical Agents cont

Filteration

Filtration helps to remove bacteria from large volumes of

fluid especially fluid containing heat-labile components such as

sera solution of sugars and antibiotics

A pore size of 02 m is effective because filters act not only

mechanically but by electrostatic adsorption of particles to their surface

Physical Agents cont

RADIATION

Non Ionisizing radiation

Types Produced by Mode of action Uses Comments

Low energy

(Infrared and

ultraviolet rays)

UV lamps DNA damage Infrared rays

Sterilization of prepacked

items such as syringes

and catheters

Ultraviolet rays

Used for disinfecting

operation threatres and

laboratories

Use of UV light

is limited by

penetration and

hazardous

Ionisizing radiation

High energy

ionizing type

(Gamma rays and

high energy

electrons such as

X-rays and

cosmic rays)

Cobalt-60

based

instruments

DNA damage For the sterilization of

antibiotics hormones

and other prepacked

disposable items such

as catheters gloves

syringes infusion sets

oils animal feeds etc

They are

expensive

They are very

effective due to

high penetrative

power

Physical Agents cont

Ultrasonic and sonic vibration

They have the property to disrupt the cells but the results have been variable

Gram negative rods are more sensitive to ultrasonic vibration whereas Gram

positive cocci spores of fungi and bacteria are resistant to the vibration

Ultrasonic devices are used in dental

However most sonic machines are not reliable for routine use

Chemical Agents cont

Properties of Ideal antiseptics or disinfectants should

Effective against all microorganisms and have a wide spectrum of

activity

Have speedy action

Be effective in presence of organic matter

Be effective in varying pH(acidic and alkaline medium)

Be stable

Also compatible with other antiseptics and disinfectants

Have high penetrating power

Not corrode metals

Not cause local irritation or sensitization

Not interfere with healing

Not be toxic if absorbed into circulationBe cheap and safe

The level of disinfection achieved depends on several factors

bull contact time

bull temperature

bull type and concentration of the active ingredients of the chemical germicide

bull the nature of the microbial contamination

Mechanisms of action of antiseptic and disinfectants

bull Oxidation of bacterial protoplasm

ndash Potassium permagnate H202 Halogens

bull Co-agulation (denaturation) of bacterial proteins amp disrupt cell membrane

ndash Phenols chlorhexidine alcohols aldehydes

bull Detergent like action uarr permeability of bacterial cell membrane

ndash Cetrimide soaps

Types of disinfectionbull High-level disinfection can be expected to

destroy all microorganisms with the exception of large numbers of bacterial spores

bull Intermediate disinfection inactivates Mycobacterium tuberculosis vegetative bacteria most viruses and most fungi does not necessarily kill bacterial spores

bull Low-level disinfection can kill most bacteria some viruses and some fungi cannot be relied on to kill resistant microorganisms such as tubercle bacilli or bacterial spores

Medical devices equipment and surgical materials are divided into three general categories based on the potential risk of

infection involved in their use

critical items

semicritical items

noncritical items

Critical items

bull Critical items are instruments or objects that are introduced directly into the bloodstream or into other normally sterile areas of the body

Examples of critical items are surgical instruments cardiac catheters implants pertinent components of the heart-lung oxygenator and the blood compartment of a hemodialyzer

Sterility at the time of use is required for these items consequently one of several accepted sterilization procedures is generally recommended

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Physical Agents cont

RADIATION

Non Ionisizing radiation

Types Produced by Mode of action Uses Comments

Low energy

(Infrared and

ultraviolet rays)

UV lamps DNA damage Infrared rays

Sterilization of prepacked

items such as syringes

and catheters

Ultraviolet rays

Used for disinfecting

operation threatres and

laboratories

Use of UV light

is limited by

penetration and

hazardous

Ionisizing radiation

High energy

ionizing type

(Gamma rays and

high energy

electrons such as

X-rays and

cosmic rays)

Cobalt-60

based

instruments

DNA damage For the sterilization of

antibiotics hormones

and other prepacked

disposable items such

as catheters gloves

syringes infusion sets

oils animal feeds etc

They are

expensive

They are very

effective due to

high penetrative

power

Physical Agents cont

Ultrasonic and sonic vibration

They have the property to disrupt the cells but the results have been variable

Gram negative rods are more sensitive to ultrasonic vibration whereas Gram

positive cocci spores of fungi and bacteria are resistant to the vibration

Ultrasonic devices are used in dental

However most sonic machines are not reliable for routine use

Chemical Agents cont

Properties of Ideal antiseptics or disinfectants should

Effective against all microorganisms and have a wide spectrum of

activity

Have speedy action

Be effective in presence of organic matter

Be effective in varying pH(acidic and alkaline medium)

Be stable

Also compatible with other antiseptics and disinfectants

Have high penetrating power

Not corrode metals

Not cause local irritation or sensitization

Not interfere with healing

Not be toxic if absorbed into circulationBe cheap and safe

The level of disinfection achieved depends on several factors

bull contact time

bull temperature

bull type and concentration of the active ingredients of the chemical germicide

bull the nature of the microbial contamination

Mechanisms of action of antiseptic and disinfectants

bull Oxidation of bacterial protoplasm

ndash Potassium permagnate H202 Halogens

bull Co-agulation (denaturation) of bacterial proteins amp disrupt cell membrane

ndash Phenols chlorhexidine alcohols aldehydes

bull Detergent like action uarr permeability of bacterial cell membrane

ndash Cetrimide soaps

Types of disinfectionbull High-level disinfection can be expected to

destroy all microorganisms with the exception of large numbers of bacterial spores

bull Intermediate disinfection inactivates Mycobacterium tuberculosis vegetative bacteria most viruses and most fungi does not necessarily kill bacterial spores

bull Low-level disinfection can kill most bacteria some viruses and some fungi cannot be relied on to kill resistant microorganisms such as tubercle bacilli or bacterial spores

Medical devices equipment and surgical materials are divided into three general categories based on the potential risk of

infection involved in their use

critical items

semicritical items

noncritical items

Critical items

bull Critical items are instruments or objects that are introduced directly into the bloodstream or into other normally sterile areas of the body

Examples of critical items are surgical instruments cardiac catheters implants pertinent components of the heart-lung oxygenator and the blood compartment of a hemodialyzer

Sterility at the time of use is required for these items consequently one of several accepted sterilization procedures is generally recommended

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Physical Agents cont

Ultrasonic and sonic vibration

They have the property to disrupt the cells but the results have been variable

Gram negative rods are more sensitive to ultrasonic vibration whereas Gram

positive cocci spores of fungi and bacteria are resistant to the vibration

Ultrasonic devices are used in dental

However most sonic machines are not reliable for routine use

Chemical Agents cont

Properties of Ideal antiseptics or disinfectants should

Effective against all microorganisms and have a wide spectrum of

activity

Have speedy action

Be effective in presence of organic matter

Be effective in varying pH(acidic and alkaline medium)

Be stable

Also compatible with other antiseptics and disinfectants

Have high penetrating power

Not corrode metals

Not cause local irritation or sensitization

Not interfere with healing

Not be toxic if absorbed into circulationBe cheap and safe

The level of disinfection achieved depends on several factors

bull contact time

bull temperature

bull type and concentration of the active ingredients of the chemical germicide

bull the nature of the microbial contamination

Mechanisms of action of antiseptic and disinfectants

bull Oxidation of bacterial protoplasm

ndash Potassium permagnate H202 Halogens

bull Co-agulation (denaturation) of bacterial proteins amp disrupt cell membrane

ndash Phenols chlorhexidine alcohols aldehydes

bull Detergent like action uarr permeability of bacterial cell membrane

ndash Cetrimide soaps

Types of disinfectionbull High-level disinfection can be expected to

destroy all microorganisms with the exception of large numbers of bacterial spores

bull Intermediate disinfection inactivates Mycobacterium tuberculosis vegetative bacteria most viruses and most fungi does not necessarily kill bacterial spores

bull Low-level disinfection can kill most bacteria some viruses and some fungi cannot be relied on to kill resistant microorganisms such as tubercle bacilli or bacterial spores

Medical devices equipment and surgical materials are divided into three general categories based on the potential risk of

infection involved in their use

critical items

semicritical items

noncritical items

Critical items

bull Critical items are instruments or objects that are introduced directly into the bloodstream or into other normally sterile areas of the body

Examples of critical items are surgical instruments cardiac catheters implants pertinent components of the heart-lung oxygenator and the blood compartment of a hemodialyzer

Sterility at the time of use is required for these items consequently one of several accepted sterilization procedures is generally recommended

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Chemical Agents cont

Properties of Ideal antiseptics or disinfectants should

Effective against all microorganisms and have a wide spectrum of

activity

Have speedy action

Be effective in presence of organic matter

Be effective in varying pH(acidic and alkaline medium)

Be stable

Also compatible with other antiseptics and disinfectants

Have high penetrating power

Not corrode metals

Not cause local irritation or sensitization

Not interfere with healing

Not be toxic if absorbed into circulationBe cheap and safe

The level of disinfection achieved depends on several factors

bull contact time

bull temperature

bull type and concentration of the active ingredients of the chemical germicide

bull the nature of the microbial contamination

Mechanisms of action of antiseptic and disinfectants

bull Oxidation of bacterial protoplasm

ndash Potassium permagnate H202 Halogens

bull Co-agulation (denaturation) of bacterial proteins amp disrupt cell membrane

ndash Phenols chlorhexidine alcohols aldehydes

bull Detergent like action uarr permeability of bacterial cell membrane

ndash Cetrimide soaps

Types of disinfectionbull High-level disinfection can be expected to

destroy all microorganisms with the exception of large numbers of bacterial spores

bull Intermediate disinfection inactivates Mycobacterium tuberculosis vegetative bacteria most viruses and most fungi does not necessarily kill bacterial spores

bull Low-level disinfection can kill most bacteria some viruses and some fungi cannot be relied on to kill resistant microorganisms such as tubercle bacilli or bacterial spores

Medical devices equipment and surgical materials are divided into three general categories based on the potential risk of

infection involved in their use

critical items

semicritical items

noncritical items

Critical items

bull Critical items are instruments or objects that are introduced directly into the bloodstream or into other normally sterile areas of the body

Examples of critical items are surgical instruments cardiac catheters implants pertinent components of the heart-lung oxygenator and the blood compartment of a hemodialyzer

Sterility at the time of use is required for these items consequently one of several accepted sterilization procedures is generally recommended

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

The level of disinfection achieved depends on several factors

bull contact time

bull temperature

bull type and concentration of the active ingredients of the chemical germicide

bull the nature of the microbial contamination

Mechanisms of action of antiseptic and disinfectants

bull Oxidation of bacterial protoplasm

ndash Potassium permagnate H202 Halogens

bull Co-agulation (denaturation) of bacterial proteins amp disrupt cell membrane

ndash Phenols chlorhexidine alcohols aldehydes

bull Detergent like action uarr permeability of bacterial cell membrane

ndash Cetrimide soaps

Types of disinfectionbull High-level disinfection can be expected to

destroy all microorganisms with the exception of large numbers of bacterial spores

bull Intermediate disinfection inactivates Mycobacterium tuberculosis vegetative bacteria most viruses and most fungi does not necessarily kill bacterial spores

bull Low-level disinfection can kill most bacteria some viruses and some fungi cannot be relied on to kill resistant microorganisms such as tubercle bacilli or bacterial spores

Medical devices equipment and surgical materials are divided into three general categories based on the potential risk of

infection involved in their use

critical items

semicritical items

noncritical items

Critical items

bull Critical items are instruments or objects that are introduced directly into the bloodstream or into other normally sterile areas of the body

Examples of critical items are surgical instruments cardiac catheters implants pertinent components of the heart-lung oxygenator and the blood compartment of a hemodialyzer

Sterility at the time of use is required for these items consequently one of several accepted sterilization procedures is generally recommended

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Mechanisms of action of antiseptic and disinfectants

bull Oxidation of bacterial protoplasm

ndash Potassium permagnate H202 Halogens

bull Co-agulation (denaturation) of bacterial proteins amp disrupt cell membrane

ndash Phenols chlorhexidine alcohols aldehydes

bull Detergent like action uarr permeability of bacterial cell membrane

ndash Cetrimide soaps

Types of disinfectionbull High-level disinfection can be expected to

destroy all microorganisms with the exception of large numbers of bacterial spores

bull Intermediate disinfection inactivates Mycobacterium tuberculosis vegetative bacteria most viruses and most fungi does not necessarily kill bacterial spores

bull Low-level disinfection can kill most bacteria some viruses and some fungi cannot be relied on to kill resistant microorganisms such as tubercle bacilli or bacterial spores

Medical devices equipment and surgical materials are divided into three general categories based on the potential risk of

infection involved in their use

critical items

semicritical items

noncritical items

Critical items

bull Critical items are instruments or objects that are introduced directly into the bloodstream or into other normally sterile areas of the body

Examples of critical items are surgical instruments cardiac catheters implants pertinent components of the heart-lung oxygenator and the blood compartment of a hemodialyzer

Sterility at the time of use is required for these items consequently one of several accepted sterilization procedures is generally recommended

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Types of disinfectionbull High-level disinfection can be expected to

destroy all microorganisms with the exception of large numbers of bacterial spores

bull Intermediate disinfection inactivates Mycobacterium tuberculosis vegetative bacteria most viruses and most fungi does not necessarily kill bacterial spores

bull Low-level disinfection can kill most bacteria some viruses and some fungi cannot be relied on to kill resistant microorganisms such as tubercle bacilli or bacterial spores

Medical devices equipment and surgical materials are divided into three general categories based on the potential risk of

infection involved in their use

critical items

semicritical items

noncritical items

Critical items

bull Critical items are instruments or objects that are introduced directly into the bloodstream or into other normally sterile areas of the body

Examples of critical items are surgical instruments cardiac catheters implants pertinent components of the heart-lung oxygenator and the blood compartment of a hemodialyzer

Sterility at the time of use is required for these items consequently one of several accepted sterilization procedures is generally recommended

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Medical devices equipment and surgical materials are divided into three general categories based on the potential risk of

infection involved in their use

critical items

semicritical items

noncritical items

Critical items

bull Critical items are instruments or objects that are introduced directly into the bloodstream or into other normally sterile areas of the body

Examples of critical items are surgical instruments cardiac catheters implants pertinent components of the heart-lung oxygenator and the blood compartment of a hemodialyzer

Sterility at the time of use is required for these items consequently one of several accepted sterilization procedures is generally recommended

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Critical items

bull Critical items are instruments or objects that are introduced directly into the bloodstream or into other normally sterile areas of the body

Examples of critical items are surgical instruments cardiac catheters implants pertinent components of the heart-lung oxygenator and the blood compartment of a hemodialyzer

Sterility at the time of use is required for these items consequently one of several accepted sterilization procedures is generally recommended

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Semicritical itemsbull These items come in contact with intact mucous membranes

but they do not ordinarily penetrate body surfaces

Examples are noninvasive flexible and rigid fiberoptic endoscopes endotracheal tubes anesthesia breathing circuits and cystoscopes

Sterilization is not absolutely essential at a minimum a high-level disinfection procedure that can be expected to destroy vegetative microorganisms most fungal spores tubercle bacilli and small nonlipid viruses is recommended In most cases meticulous physical cleaning followed by an appropriate high-level disinfection treatment gives the user a reasonable degree of assurance that the items are free of pathogens

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Noncritical items

bull Noncritical items are those that either do not ordinarily touch the patient or touch only intact skin

Such items include crutches bedboards blood pressure cuffs and a variety of other medical accessories

These items rarely if ever transmit disease Consequently washing with a detergent may be sufficient

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

bull Items must be thoroughly cleaned before processing because organic material (eg blood and proteins) may contain high concentrations of microorganisms Also such organic material may inactivate chemical germicides and protect microorganisms from the disinfection or sterilization process

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

For noncritical itemscleaning can consist only of

1) washing with a detergent or a disinfectant-detergent

2) rinsing

3) thorough drying

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Steam sterilization

bull Steam sterilization is the most inexpensive and effective method for sterilization

bull Steam sterilization is unsuitable for processing plastics with low melting points powders or anhydrous oils

bull Items that are to be sterilized but not used immediately need to be wrapped for storage

bull Sterility can be maintained in storage for various lengths of time depending on the type of wrapping material the conditions of storage and the integrity of the package

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Monitoring of steam sterilization processes

bull to check the highest temperature that is reached during sterilization and the length of time that this temperature is maintained

bull heat- and steam-sensitive chemical indicators can be used on the outside of each pack

bull a large pack might have a chemical indicator both on the outside and the inside to verify that steam has penetrated the pack

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Microbiological monitoring

Microbiological monitoring of steam sterilizers is recommended at least once a week with commercial preparations of spores of Bacillus stearothermophilus (a microorganism having spores that are particularly resistant to moist heat thus assuring a wide margin of safety)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Ethylene oxide gas sterilization

bull It is a more complex and expensive process than steam sterilization

bull It is usually restricted to objects that might be damaged by heat or excessive moisture

bull Before sterilization objects also need to be cleaned thoroughly and wrapped in a material that allows the gas to penetrate

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

bull Because ethylene oxide gas is toxic precautions (eg local exhaust ventilation) should be taken to protect personnel All objects processed by gas sterilization also need special aeration according to manufacturers recommendations before use to remove toxic residues of ethylene oxide

bull Chemical indicators need to be used with each package to show that it has been exposed to the gas sterilization process

bull Moreover it is recommended that gas sterilizers be checked at least once a week with commercial preparations of spores usually Bacillus subtilis

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

bull Powders and anhydrous oils can be sterilized by dry heat Microbiological monitoring of dry heat sterilizers usually provides a wide margin of safety for dry heat sterilization

bull Liquid chemicals can be used for sterilization and disinfection when steam gas or dry heat sterilization is not indicated or available

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Chloroxylenol (Dettol)

bull Phenol derivative

bull Does not co-agulate proteins

bull Non corrosiveNon irritating to skin

bull Commercial 48 solution used for surgical antisepsis

bull Skin cream and soap 08

bull Mouth wash 1

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Oxidizing agents

bull Potassium permagnate

ndash Purple crystals highly water soluble liberates oxygen which oxidizes bacterial protoplasm

ndash Used for gargling irrigating wounds urethra (condy`s lotion diluted solution of 14000 to 110000 )

ndash High conc cause burns

ndash It is also used to disinfect water in ponds

ndash Stomach wash in alkaloidal poisoning

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Oxidizing agents

Hydrogen Peroxide

ndash liberates nascent oxygen which oxidizes necrotic matter amp bacteria

ndash Helps in loosening amp removing slough ear wax etc

Benzoyl Peroxide

ndash Widely used drug for acne

ndash liberates O2 in presence of water which kills bacteria specially anaerobes

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Halogens

bull Iodine

bull Iodophores

bull Chlorine

bull Chlorophores

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Iodine

bull Rapidly acting broad spectrum (bacteria fungivirus)

bull Acts by iodinating and oxidizing microbial protoplasm

bull Used for cuts degerming skin beforesurgery

bull Adverse effect cause burns amp blisters

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Iodophores

bull Known as povidine iodine

bull Non toxic non staining prolonged action

bull Used on boils furunculosis burns ulcers tinea surgical srub disinfecting surgical instruments non specific vaginitis

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Chlorine

bull potent germicide Kills pathogens in 30 sec used to disinfect urban water supplies

bull 01 to 025 ppm

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Cholorophores

(1) Chlorinated lime (bleaching powder)

ndash obtained by action of chlorine on lime

ndash used to disinfect drinking water

(2) Sodium hypochlorite

ndash Powerful disinfectant used in dairies for milk cans

ndash Too Irritant to be used as antiseptic

ndash Root canal therapy in dentisry

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Biguanides

Chlorhexidine (Savlon)

ndash Acts by disrupting bacterial cell membrane amp denaturation of bacterial proteins

ndash Non irritant more active against gram +vebacteria

ndash Used in for surgical scrub neonatal bath mouth wash amp general skin antiseptic

ndash Most widely used antiseptic in dentisry 012-02 oral rinse or 05 -1 tooth paste

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Quarternary ammonium antisepticscetrimide

bull Detergents Cidal to bacteria fungi amp viruses

bull Act by altering permeability of cell membrane

bull Efficiently remove dirt and grease

bull Widely used as antiseptics amp disinfectants for

surgical instruments gloves etc

bull Combined with chlorhexidine (savlon)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Soaps

bull Anionic detergents

bull Weak antiseptics with cleansing action

bull Washing with soap and warm water one of the most effective methods of preventing disease transmission

bull Affect only Gm+ bacteria

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Dyes

Gentian violet

ndash Active against bacteria (gram + ve) fungi

ndash Used on chronic ulcers furunculosis bed sores ring worms

Acriflavine

ndash Active against gram +ve bacteria amp gonocci

ndash suitable for chronic ulcers amp wounds

ndash Do not retard healing non irritant

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

Microbial Characteristics and Microbial Control

Figure 711

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)

No Disinfectant is substitute for the following Procedures

bull 1048766 Hand washing (hand hygiene)bull 1048766 The use of personal protective equipment (eg

gloves) when handling blood bodybull substances excretions and secretionsbull 1048766 Appropriate handling of patient care equipment

and soiled linenbull 1048766 The prevention of needle sticksharp injuriesbull 1048766 Environmental cleaningbull 1048766 Appropriate handling of waste andbull 1048766 Taking care of yourself (eg immunization)