BIO-MEDICAL

WASTE

DEFINITION

• Biomedical wastes are wastes, which are generated during the diagnosis, treatment or immunization of human beings or animals or in research activities pertaining thereto or in the production or testing of biologicals.

• Common producers of biomedical waste include hospitals, health clinics, nursing homes, medical research laboratories, veterinarians, and funeral homes.

• Bio-medical wastes are infectious and hazardous and need to be managed carefully.

Hazards of biomedical waste

• Infection and diseases- cholera, T.B, hepatitis B, HIV, plague

• Genotoxicity and Cytotoxicity

• Chemical toxicity

• Radioactivity hazards-headache, vomiting, dizziness, DNA damage, carcinogenesis

• Physical injuries – by sharps like needles, blades

• Air, water and land pollution

• Public sensitivity-visual impact of healthcare waste specially anatomical waste.

BIO-MEDICAL WASTE

(MANAGEMENT AND HANDLING)

RULES,1998.• Came in to force on 28th July,1998.

• Prescribed by Ministry of Environment & Forests, under the Environment Protection Act of India.

• These rules provide a system for regulating & handling Bio-Medical Wastes.

• Includes collection, segregation at source, norms for packaging, labelling and options for treatment and disposal along with the standard for treatment technologies.

• Applicable to all persons who generate, collect, receive, store, transport, treat, dispose or handle bio-medical waste in any form.

Salient features of the rule

• Categorization of waste.

• Duty of every occupier to ensure that such waste is handled without adverse effect to human health and environment.

• Bio-medical waste should not be mixed with other waste.

• Segregation at source according to colour codes and labelled properly.

• Untreated bio-medical waste shall not be stored more than 48 hours.

• Bio-medical waste should be transported only in vehicles authorized by competent authority.

• Maintenance of records.

• Non-compliance : failure to comply with any provision is punishable with upto 5 years imprisonment or a fine of Rs.1 lakh or both.

• SCHEDULE I - Contains the categories of bio-medical waste.

• SCHEDULE II - Contains colour coding and type of container for disposal of different bio-medical waste categories.

• SCHEDULE III - Contains labels for biomedical waste containers/bags.

CATEGORY WASTE CONTENTS

1 HUMAN ANATOMICAL WASTE

HUMAN TISSUES,ORGANS,BODY PARTS

2 ANIMAL WASTE ANIMAL TISSUES, ORGANS, CARCASSES,BLEEDING PARTS, FLUIDS, BLOOD

3 MICROBIOLOGY AND BIOTECHNOLOGYWASTE

WASTES FROM LAB CULTURES, VACCINES, TOXINS, ANIMAL CELL CULTURES

4 WASTE SHARPS NEEDLES, SYRINGES, SCALPELS, BLADES etc.

5 DISCARDED MEDICINES AND CYTOTOXIC DRUGS

OUTDATED, CONTAMINATED MEDICINES

CATEGORIES(SCHEDULE I)

6 SOILED WASTE CONTAMINATED COTTON,LINEN,DRESSINGS, SOILED PLASTER CASTS, BEDDINGS etc.

7 SOLID WASTE GENERATED FROM DISPOSABLES OTHER THAN SHARPS SUCH AS TUBINGS, CATHETERS, I.V. SETS etc.

8 LIQUID WASTE GENERATED FROM LABORATORY AND WASHING, CLEANING, HOUSEKEEPING AND DISINFECTING ACTIVITIES

9 INCINERATION ASH ASH FROM INCINERATION OF BIOMEDICAL WASTE

10 CHEMICAL WASTE INSECTICIDES,DISINFECTANT

COLOUR CODING AND TYPE OF

CONTAINER FOR DISPOSAL OF BIO-

MEDICAL WASTES (SCHEDULE II)COLOUR CODING

TYPE OF CONTAINER

WASTE CATEGORY

TREATMENT

YELLOW PLASTIC BAG 1,2,3,6 INCINERATION/DEEP BURIAL

RED DISINFECTED CONTAINER/ PLASTIC BAG

3,6,7 AUTOCLAVING/ MICROWAVING/ CHEMICAL TREATMENT

BLUE/ WHITE TRANSLUCENT

PLASTIC BAG/ PUNCTURE PROOF CONTAINER

4,7 AUTOCLAVING/ MICROWAVING/ CHEMICAL TREATMENT & DESTRUCTION/ SHEDDING

BLACK PLASTIC BAG 5,9 & 10 DISPOSAL IN SECURED LANDFILL

LABELS (SCHEDULE III)

NOTE: LABEL SHALL BE NON WASHABLE AND PROMINENTLY VISIBLE.

SEGREGATION

• It is the separation of waste into different streams and the treatment of each stream to ensure complete sterilization and recycling.

• It should be done at point of generation.

• Non-infectious wastes must be kept separate from infectious wastes at all costs.

• Helps in reduction of :

1. Total treatment cost.

2. Impacts of waste on community.

3. Chances of infecting healthcare workers.

• Wastes are segregated in containers according to the prescribed colour codes.

• Yellow-infectious anatomical wastes, contaminated soiled dressings, body parts etc.

• Red-infectious plastics like gloves, IV sets, tubings, catheters etc.

• Blue-glass wastes.

• Black-cytotoxic drugs, expired medicines, incinerator ash, chemical wastes.

• White-recyclable non-infected general waste.

• Green- collecting and transporting food waste from wards, canteens etc.

TRANSPORT

• Transported in wheeled trolleys/ containers/ carts only in vehicles authorized for the purpose.

• They should be :

1. Easy to load and unload by hand.

2. No sharp edges.

3. Easy to clean.

4. Fully enclosed to prevent spillage.

• Disinfection should be done daily.

• Transportation should always be properly documented.

• Vehicles should carry a consignment note from point of collection to treatment facility.

TREATMENT

• Chemical treatment

• Thermal treatment

• Mechanical treatment

• Irradiation process

• Biological process

• Inertization

• Land disposal

Chemical treatment

• Uses chemicals to destroy pathogenic organisms from any inanimate object.

• Most suitable for treating liquid wastes- blood, urine, stools, hospital sewage.

• Sodium hypochlorite

• Tincture iodine

• Ethyl alcohol

• Glutaraldehyde

• Formaldehyde

• Savlon

• Isopropyl alcohol

Thermal treatmentThermal energy is used to destroy pathogens in the waste.

• Low-Heat Thermal Process : to decontaminate the waste at temperatures insufficient to cause chemical breakdown or to support combustion or pyrolysis , operate between 93°C -177°C.

The two basic categories of low-heat thermal processes are:

(a) Wet heat-use of steam to disinfect waste.

Autoclave, Microwave treatment.

(b) Dry heat-heat via conduction, convection & radiation.

Hot air ovens.

• Medium-Heat Thermal Process : temperatures between 177°C-370°C and involve the chemical breakdown of organic material.

• High-Heat Thermal Process: temperatures ranging from 540°C-8300°C or higher-Incineration and hydroclaving.

Autoclaving

• Autoclave – used for microbiology and biotechnology waste.

• Wet heat method

• Conditions:

• Temperature-121⁰C

• Holding time-15 min.

• Pressure-15 pounds per sq.inch.

AUTOCLAVE

Microwaves• Wet heat method

• Waves with Frequency of about 3000 MHz are used to destroy micro-organisms.

• These penetrate materials & create vibrations in molecules.

• This vibration generates friction which produces heat to disinfect the waste material.

• Heat is produced at 95-100 ⁰C for a holding period of 25 to 30 minutes. MICROWAVE

Hot air oven• Dry heat method

• Oven is electrically heated

• Fan for adequate distribution of hot air in the chamber.

• Thermostat-maintains temperature of chamber air.

• Temperature-160⁰C

• Holding time-2 hours

Incineration• Burning of waste at high temperatures

in presence of oxygen under controlled conditions.

• Used for soiled dressings, animal carcasses beddings & pathological materials.

• Waste volume and weight are reduced.

• Waste is burnt in primary chamber at 800-850 ⁰C.

• Volatile gases emitted are again burnt in secondary chamber at 1050-1100 ⁰C.

• Cycle time for entire operation – 1 hour.

• Requires skilled personnel & proper handling.

INCINERATOR

Mechanical treatment

• used to change the physical form or characteristics of the waste either to facilitate waste handling or to process the waste in conjunction with other treatment steps.

The two primary mechanical processes are

• Compaction - used to reduce the volume of the waste

• Shredding - used to destroy plastic and paper waste to prevent their reuse. Only the disinfected waste can be used in a shredder.

Irradiation processes• exposes wastes to ultraviolet or ionizing radiation in

an enclosed chamber. • These systems require post shredding to render the

waste unrecognizable.

Biological processes• using biological enzymes for treating medical

waste.• not only decontaminate the waste but also cause

the destruction of all the organic constituents so that only plastics, glass, and other inert will remain in the residues.

Inertization

• Involves mixing waste with cement and other substances before disposal, thus making them inert.

• To prevent toxic substances in waste from contaminating the ground or surface water.

• Mixture has

• 65 % waste

• 15 % lime

• 15 % cement

• 5 % water

Land disposal

Sanitary landfills are used to dispose biomedical waste.

Criteria for using landfills -

• Full or partial hydrogeological isolation.

• Appropriate engineering preparations.

• Trained staff should supervise its functioning.

• Planned waste emplacement and covering: waste should be spread in layers and compacted.

MINIMIZATION

• By reducing waste at source – avoiding wastage.

• Using recyclables – e.g. using sterilizable glassware and stainless steel equipments.

• By adopting a rational purchasing policy and finding environment-friendly alternatives.

• Segregation at source.

• Stock management (inventorying regularly & replacing i.v. fluids, blood & drugs so that there is no wastage due to spoilage or expiry.