Handling of Hazardous Chemicals

Igniting Minds... Energizing Lives…Haldia Refinery

K. G. PochirajuDM(F&S)

The hazardous substances are classified into eight classes. These are as under :

CLASS 1 EXPLOSIVES 

CLASS 2 GASES, COMPRESSED LIQUEFIED DISSOLVED OR DEEPLY REFRIGERATED, INFLAMMABLE GASES, POISON (TOXIC)

GASES.

CLASS 3 INFLAMMABLE LIQUIDS

CLASS 4 INFLAMMABLE SOLIDS, SUBSTANCES LIABLE TO SPONTANEOUS CONBUSTION; SUBSTANCES WHICH ON CONTACT WITH WATER EMIT INFLAMMABLE GASES.

Division 4.1 Inflammable solids

Division 4.2 Substances liable to spontaneous combustion.

Division 4.3 Substances, which in contact with water, emit inflammable gases.

CLASS 5 OXIDISING SUBSTANCES

Division 5.1 oxidizing substances

Division 5.2 Organic peroxides

CLASS 6 POISONOUS (TOXIC) AND INFECTIOUS SUBSTANCES

Division 6.1 Poisonous (toxic) substances

Division 6.2 Infectious substances

CLASS 7 RADIOACTIVE SUBSTANCES

CLASS 8 CORROSIVES

Hazard Class 1 - ExplosivesHazard Class 1 - Explosives

• Subdivided into 6 divisions1.1 - Mass explosion hazard

1.2 - Projectile hazard

1.3 - Fire, minor blast or projectile

1.4 - Minor explosion

1.5 - Very insensitive explosives

1.6 - Extremely insensitive

• Pressurized or liquified– Compressed nitrogen and liquified petroleum

gases (LPG) are examples

• Product and container present hazards

• Three Subdivisions – 2.1 - Flammable gases– 2.2 - Non-Flammable, Non-Poisonous– 2.3 - Poisonous Gases

Hazard Class 2 - GasesHazard Class 2 - Gases

Hazard Class 3 - Flammable/Combustible Liquids

Hazard Class 3 - Flammable/Combustible Liquids

• Flammable Liquids can be ignited at room temperature

• Combustible Liquids require some degree of pre-heating to ignite

• Number 1 rule - eliminate ignition sources

Hazard Class 4 - Flammable Solids

Hazard Class 4 - Flammable Solids

• Three subdivisions4.1 - Flammable Solids

4.2 - Spontaneously Combustible

4.3 - Dangerous when wet

Hazard Class 5 - Oxidizers and Organic Peroxides

Hazard Class 5 - Oxidizers and Organic Peroxides

• Oxidizers release oxygen to enhance or intensify burn

• With strong fuels, oxidizers can create conditions which which can lead to violent combustion

• Many Organic Peroxides are very unstable

Hazard Class 6 - Poisonous and Infectious Substances

Hazard Class 6 - Poisonous and Infectious Substances

• Poisonous to human– Can include severely irritating

substances

– “Tear Gas”, Hydrocyanic acid, Carbon Tetrachloride

• Infectious Substances– Potential to cause diseases in humans

– Anthrax, human blood and many body fluids

Hazard Class 7 - Radioactive Materials

Hazard Class 7 - Radioactive Materials

• Ionizing radiation hazard

• Exposure does not always result in contamination

• Safety Rules:– Time, Distance and Shielding

• Shipped in specialized containers

Hazard Class 8 - CorrosivesHazard Class 8 - Corrosives

The word "pyrophoric" is derived from the Greek for "fire-bearing". According toWebster's dictionary, "pyrophoric material" means "any material igniting spontaneously orburning spontaneously in air when rubbed, scratched, or struck, e.g. finely dividedmetals".Iron sulfide is one such pyrophoric material that oxidizes exothermically when exposed toair. It is frequently found in solid iron sulfide scales in refinery units. It makes nodifference whether these pyrophoric sulfides exist as pyrite, troilite, marcasite, orpyrrhotite. It is formed by the conversion of iron oxide (rust) into iron sulfide in anoxygen-free atmosphere where hydrogen sulfide gas is present (or where the concentrationof hydrogen sulfide (H2S) exceeds that of oxygen). The individual crystals of pyrophoriciron sulfides are extremely finely divided, the result of which is that they have anenormous surface area-to-volume ratio.When the iron sulfide crystal is subsequently exposed to air, it is oxidized back to ironoxide and either free sulfur or sulfur dioxide gas is formed. This reaction between ironsulfide and oxygen is accompanied by the generation of a considerable amount of heat. Infact, so much heat is released that individual particles of iron sulfide become incandescent.This rapid exothermic oxidation with incandescence is known as pyrophoric oxidationand it can ignite nearby flammable hydrocarbon-air mixtures.

What is Pyrophoric Iron Oxidation?

STORAGE OF CHEMICALS IN BULK

(Attempt should be made to find suitable less hazardous alternate chemicals, to replace the hazardous chemical. The inventory of all hazardous chemicals for that matter must be kept as minimum as possible.

The tanks should be located so as not to pose safety problems due to leakage and reaction with other chemicals stored nearby. The environment at the location must be compatible with the chemical stored.

Oxidising Agents : Oxidising substances must be stored away from all flammable materials even if they are only slightly flammable. Oxidising material must be kept away from substance which are reducing agents.

Water Sensitive Substances : These substances react with water or steam to produce flammable or explosive gases and evolve heat, eg.. Conc. acids like sulphuric acid etc. Conc. Alkali like sodium hydroxide react with water later to evolve heat. Such materials must not be stored in areas where water flooding from pipe leakages or leaky roofs can happen

* Corrosive Chemicals : The flooring of the area where corrosive chemicals are stored, shall be impervious and made of corrosion resistant materials.

* The storage tank and foundation should be of suitable material of construction to prevent corrosion.

* The connections and openings to the tank should be as minimum as possible so that the possibility of leakage and maintenance hazards are minimized.

* The tanks should be fitted with vents/relief systems of adequate capacity discharging to a safe height. Capacity requirement in case of high vapour evolution resulting from heating due to fire of adjacent tank also should be considered. Wherever atmospheric release of the vapour is not advisable, the relief should be routed to a neutralising system. Flame arrestors are recommended for the vents of atmospheric storage tanks containing Class A (flash point less than 23 degree centigrade) chemicals. The location of flame arrestor must be easily accessible for periodic inspection to ensure that flame arrestor is free of any choking.

* The tank should have provision for emergency evacuation of its stock to a safer location in case of emergency like fire, tank failure etc. using suitable pump out system. Use of double isolation valve – gate and globe valve in series on the drain outline is recommended.

 * Each storage tank should have necessary instruments to monitor its level, pressure and temperature preferably with remote indications at control room. Abnormal rise in level / pressure / temperature should alert control room by alarm. Quite often, the level gauges pose problems of choking, leakage from drain connections, leakage from broken gauge glasses leading to accidents. Hence, it is suggested to have guarded, illuminated level gauges. Level gauges should have provision for in-situ cleaning.

Wherever possible any leakage of hazardous chemicals must be detected and alarm should be annunciated at control room.

 

 

The tank should have a dyke of suitable material (compatible with the chemical) of volume equal to the volume of the larger storage tank. The dyke should have facility to:

(a) drain off rain water into storm water channel ;

(b) route high volume spillage / leakage to suitable neutralizing pit nearby

(c) discharge safe effluent to oily water system, as applicable.

 The isolation valves on dyke drains should be located outside the dyke.

Fire access roads should be provided to storage area. The storage tanks / area should have suitable fire protection and fire fighting facility.

Adequate communication facility like public address / telephone must be made available for interacting with control room, fire stations, medical units etc.

The name of chemical, type of hazard, emergency operational instructions, antidote first aid etc. should be displayed near each tank.

Electrical Safety : All cables and electric fittings shall be constructed, installed, protected, operated and maintained in such a manner so as to prevent risk of open sparking

STORAGE OF CHEMICALS IN DRUMS / OTHER CONTAINER

Drum storage of hazardous chemicals (liquids) pose potential hazard compared to bulk storage in that

(a) each drum of a cluster of drum can become a source of leakage;

(b) the drums normally being less resistant to fire would collapse faster escalating and spreading of fire to other drums of the stack. Hence following guidelines Shall be considered

The drums should never be filled full with the liquid chemical. There should be sufficient ullage to take care of thermal expansion.

The drums should preferably be stored in a well ventilated shed (preferably away from process units) with impermeable floor sloping away from drums.

There should be provision to collect accidental spills for safe disposal.

The drums should be stacked in a single tier with the bung (lid) up in an orderly manner so that all parts of the storage space are accessible.

 

Empty drums should be removed away and made free of its contents before being kept in safe place. 

Periodic site inspection should be carried out to ensure that there is no leakage from any of the drums.

Where combustible solid materials are stored,efficient dust collection system and good house keeping should be ensured.

HANDLING OF HAZARDOUS CHEMICALS

UNLOADING OF TANK TRUCKS / TANK WAGONS

 Before the tanker enters the industry premises, the tanker is to be inspected for authorized entry and safe & sound condition of the tanker, its contents and that of the prime mover. Tankers entering plant are to be fitted with flare arresters on their exhaust.

The quality of the chemical in the tanker should be ascertained before unloading to avoid contamination of chemical already at storage.

In case of flammable chemicals, the prime mover (engine) should be kept of. The tanker should be properly blocked from movement before connections are made for unloading hazardous chemicals.

Pressurizing with air / inert gas for unloading should be avoided. It is recommended to use pumps / vacuum systems for unloading. Pumps should preferably be of seal less type and valves should be of glandless types. Solid chemicals in bulk should be handled with lifting machines and conveyors

Coupling used for connecting hose to tanker must be leak proof. Flange connections are preferred. Where threaded connections are used, the threaded portion should be properly preserved against corrosion / wearing of threads and thoroughly inspected before connections are made.

The unloading hose should be devoid of cracks & blisters and should be capable of withstanding whatever pressure developed during unloading operation. The hose should be hydro-tested at a frequency guided by experience. Proper records of hydro-test should be maintained.

Same hose should not be used for unloading different chemicals. Hoses for different chemicals should be marked with different colour stripes for easy identification

For flammable chemicals, the tanker and the hose are to be properly earthed before starting unloading operation. Unloading should preferably be done in day time

The operating staff must use suitable personal protective clothing / equipment. Suitable breathing canisters and first aid box must be available at site for use in case of emergency.

The unloading systems should have facility to vent / drain the remaining chemical in the hose to a suitable safe point. The hose should be kept blinded when hot in use.

EMERGENCY INFORMATION PANEL

LIQUEFIED PETROLEUM GAS (LPG)

UN NO. 1075

HAZCHEM 2WE

IN EMERGENCY DIAL

INDIAN OIL CORPORATION LIMITED

SITE OFFICE

(03224) 223710 /223709

Special Advice: Avoid contact with liquefied liquid or vapour. Stay upwind. Evacuate area. Contain spillage. Disperse vapour with water.

Notes for guidance

V - Can be violently or even explosively reactive. BA - Use breathing apparatus plus protective

gloves. FULL Use full body protective clothing with breathing apparatus. DILUTE Wash to drain with large quantities of water.

CONTAIN Prevent spillage from entering drains or watercourses.

WATER FOG In the absence of fog equipment, a fine spray may be used.

DRY AGENT Water must not be allowed to come in contact with the substance at risk.

HAZCHEM Code

HAZCHEM CodeEAC uses only two or three characters

One of the numerals 1,2,3 or 4 followed by one or two alphabets which signify

•what fire - extinguishing agent should be employed•whether the spillage should be contained or can be diluted with water•whether the substance is violently reactive•what personal protective equipment should be used•whether evacuation of the surrounding area should be considered.

First Character in HAZCHEM Code

 This specifies the extinguishing medium to be used.1-    Water jet 2-    Water fog3-    Foam 4- Dry agent

However, the first character needs to be interpreted as  

1. Other media 2,3 and 4 also can be used2. Other media 3 and 4 also can be used3. Other medium 4 also can be use4. Only 4 can be used

2nd CharacterThe 2nd Character will be P,R,S,T,W,X,Y and Z The 2nd Character indicates if the spill can be diluted with water or should be contained. P,R,S,T - Dilution with water is allowedW,X,Y,Z - Dilution with water is not allowed. Should be contained

These alphabets also indicate•if the material is violently reactive•the type of personal protection required

 P,S,W,Y - Violently reactiveP,R,W,X - Full protection neededS,T,Y,Z - Breathing Apparatus ( BA) neededS,T,Y,Z - BA needed for Fire only ( in black background)

Third Character  There is only one alphabet “E”It indicates consideration for evacuation.

Vehicle Related Precautions

Do not cook inside the vehicle which carries hazardous material.

Do not burn a fire for any purpose near the vehicle .

Never overload or have a tailgate load.

Do not trans-ship material from one vehicle to another unless in emergency and with proper precautions- away from public roads , under strict supervision to loaders / drivers

The engine must remain switched off during the entire operation.

Ensure that the vehicle carries emergency flash light for parking , changing tyres ,etc .

Also ensure that it has adequate reflective triangles on the vehicle for night visibility when parked or moving.

The vehicle must carry a fire extinguisher fixed at an easily accessible place.

Material Safety Data Sheet

Contains the following Information:

1. Chemical Identity

2. Physical & Chemical Data

3. Fire & Explosion Hazard

4. Reactivity Data

5. Health Hazard Data

6. Preventive Measures

7. Emergency & First-Aid Measures

8. Additional Information/References

Where is it available?

A. In hard fashion at all Control rooms

B. On intranet-OISD STANDARDS-114 – In soft fashion.

Material Safety Data Sheet of AmmoniaChemical Identity

Formula: NH3 Hazchem Code : 2 PE

CAS No. 7664-41-7 UN. No. 1005

Physical & Chemical Data

Boiling Point/Range -33.4oC Physical State : Liquefied Compr.Gas

Appearance : Colourless Odour : Strong Pungent Odour

V.P: 7600 mm Hg @ 250 C Sol.in Water : Very Soluble

pH-11.6

Fire & Explosion Hazard

 Flammability No LEL 16.0 % UEL 25.0%

Auto ignition Temperature oC 651.0 

Explosion Sensitivity to Impact Stable 

Hazardous Combustion products Emits toxic fumes of NH3 & NOx

 Combustible Liquid Yes Explosive Material No Corrosive Material No 

Flammable Material No Oxidiser No Pyrophoric Material No

 

Reactivity Data

Chemical Stability Stable 

Incompatibility with Strong Oxidisers, Calcium hypochlorite, Gold, Mercury, Silver, Halogens,

Other material Acetaldehyde, Acrolein.

Reactivity Reacts with Silver chloride, Silver

nitrate,Silver azide, chlorine,

bromine,iodine, heavy metals and their

compounds, Incandescent reaction

when heated with Calcium.

Hazardous Reaction Products Reacts with Silver chloride, Silver nitrate, Silver Azide and Silver Oxide

form explosive silver nitride.

 

Health Hazard Data

Routes of Entry Inhalation, Skin or Eyes Effects of Exposure/ 700 ppm causes eye irritation and permanent injury may result if prompt medical remedial measures are not taken. 5000 ppm may cause death from spum inflammation, or edema of the larynx. Contact of the liquid with skin freezes the tissues and causes the caustic burns.

Emergency TreatmentInhalation : Remove the victim to fresh air and provide artificial respiration or oxygen, if needed. Skin and Eyes : Wash the affected area with plenty of water for 15 mins. Seek Medical Aid.

L.D50 (Oral-Rat) 350 mg/kg TLV (ACGIH) 25 ppm 18 mg/m3 STEL 35 ppm 27 mg/m3

NFPA Hazard Signals Health Flammability Reactivity 2 1 0

PREVENTIVE MEASURESPersonal Protective Equipment: Avoid contact with liquid or vapours. Provide rubber boots, safety goggles, self-contained breathing apparatus, gas mask and protective clothing in case of liquid ammonia.

Handling and Storage Avoid storing along with oxidizing materials and away from all possible Precautions sources of ignition. Store in well ventilated flame resistant locations.

 EMERGENCY & FIRST-AID MEASURESFIRE Stop flow of gas. Use water spray or fog.Special Procedure Keep the containers cool by spraying water if exposed to heat or flame.Unusual Hazards Gas is suffocating.

SPILLS Contain leaking liquid on sand or earth, allow to evaporate. Dilute the vapours with plenty

of water.

Waste Disposal Method Put into a large vessel containing water, neutralise with HCl and discharge into sewer with sufficient water.

 

ADDITIONAL INFORMATION/REFERENCES

LC50 : 30,000 ppm/5M (ihl-hmn). A human poison by an unspecified route. Difficult to ignite. NH3 and air in a fire, can detonate. Potentially violent or explosive reactions on contact with inter halogens. Forms sensitive explosive mixture with air and hydrocarbons. Those affected with eye and pulmonary diseases should avoid exposure to Ammonia.

THANK YOU

Igniting Minds... Energizing Lives…Haldia Refinery