working in chemical factories and dwelling nearby
are exposed to various types of chemical hazards.
Inflammable, explosive, toxic, corrosive, reactive,
radio active, oxidising, reducing, decomposing, compatible
and hidden hazardous nature of chemicals pose material
or property hazards. In process, chemical and physical
change, chemical reaction, pressure, temperature,
level, flow, quantity and other parameters create
process hazards. The vessels and equipment in which
the chemicals are stored, handled or processed, pose
vessel hazards. The inadequate, defective, under designed
or wrongly modified control devices or failure thereof
cause control hazards. Fire or explosion cause fire
hazards. Effluent disposal and gaseous emissions bring
pollution and toxic hazards. Leaks, spills and splashes
cause handling hazards. Absence, non-use or failure
of fire fighting equipment, personal protective equipment,
emergency control devices reveal accident and emergency
hazards. All other unsafe working conditions and unsafe
actions pose a variety of hazards that all need to
be prevented and controlled.
Many safety measures are available to deal with above
hazards. Identification of contents, properties, hazards
and quantity of chemicals, their content minimisation,
proper storing, handling and packing; auto control,
recording and warning devices for level, pressure,
vacuum, temperature, flow, feed, speed, cooling, heating,
stirring, discharge, contamination; remote control
devices, proper ventilating, exhaust, scrubbing, neutralising,
inactivating and incinerating devices; monitoring,
measuring, recording, tripping, correcting and controlling
system, fire fighting and personal protective equipment,
emergency and disaster planning, controls and all
engineering well designed process and plant layout
and fully safe actions of work-people are utmost necessary
to fight these hazards and to control over them. The
basic steps in short are as follows :
Identification of Health (Toxic) Hazards :
Types of effects are -
Allergy, Irritation, Oxygen deficiency (asphyxiation),
Systemic poisoning (eg damage to liver, kidney, CNS,
reproductive system etc.), Cancer, Damage to unborne
foetus(teratogenesis), Genetic effects on future generations
(mutagenesis), Dust effect (pneumoniosis).
Some effects are acute (local or short term) and some
are chronic (long term, delayed or after repeated
Factors creating effects are -
Type of concentration of chemical, Combined effects
of mixtures, Properties of the material including
its toxicity, Work methods, Nature of exposure (short
term, long term) Routes of entry (through nose, mouth
or skin) and Individual susceptibility.
Identification of other hazards :
Fire and Explosion Hazards :
Heat generation due to chemical reaction, Open flame,
Radiant heat, Fricton, Spontaneous combustion, Electric
current, Static electricity etc.
Fuel or Solvents -
Low flashpoint and Low boiling point liquids, Gases
and Solids (dusts, powders, lumps, crystals)
Atomic Radiation -
Radioactive substances and Radiation processes (X-ray,
NDT, Nuclear power plant etc.)
Preventive & Control Measures :
Six Basic Principles -
· Elimination of substance or process.
· Substitution of safer alternative.
· Distance, Guard, Enclosure, Isolation, Shielding
or Segregation of hazardous process.
· Ventilation, general & local exhaust.
· Personal Protective Equipment.
· Personal hygiene.
Management Control -
Identification, MSDS, Labelling, Safe storage, Safe
Transfer procedure, Safe handling & use, Safe
processes & operations, Safe disposal methods,
Good housekeeping, Measurement & assessment (Monitoring),
Medical examination, record and treatment (medical
surveillance), Record-keeping of work exposure monitoring,
environmental or air quality monitoring, medical and
biological monitoring, Training & education to
workers and Supervision including safety work permits
and safe work methods.
Emergency Control Procedures :
Speedy Leak & Spill Control procedures.
· Emergency shut-down procedure.
· On site emergency plan.
· Off site emergency plan.
· Mutual aid arrangement with neighbouring
· Retainer ship for help at the time of emergency.
· Regular rehearsal of emergency procedures
(drill), updating and reviewing of the plan.
(PROPERTY) HAZARDS AND CONTROL
a list of all raw materials, products, by-products
and intermediates. Identify them by their nature of
hazard and risk potentials. Classify them as inflammable,
explosive, toxic, corrosive, radioactive, reactive,
oxidising, irritant, unstable, compressed gases, dust
and others. Also note their hazardous properties viz.
boiling point, flash point, LEL, UEL, LD, LC, TLV,
MAC, IDLH, density, solubility etc., to understand
the ill-effects of the chemical. Reference No. 1 to
4 given at the end of this chapter explain all such
terms and give them for various chemicals. Reference
No. 11 gives such hazardous properties of some selected
The chemicals may cause either physical hazards or
health hazards. The physical hazards are caused due
to dust, corrosive, explosive, flammable and reactive
chemicals, compressed gases and oxidisers. The health
hazards are caused due to toxic, irritant and carcinogenic
chemicals. Carcinogenic causes cancer. Mutagenic causes
inherited changes and teratogenic causes harm to unborn.
Micro-organisms and radioactive chemicals also cause
health hazards. The hazards are also classified as
first and second degree hazards. The first degree
hazards are caused by corrosive, flammable, explosive,
toxic and oxidising chemicals, heat or ignition source,
human error and failure of equipment etc. The second
degree hazards injure life and property and include
fire, explosion, toxic exposure, corrosive chemicals,
collision, slipping, falling etc.
Identification of Chemicals
of chemicals begins with the knowledge of basic chemistry.
Refer Table No. 1 in Chapter 32 to identify first
some commonly used elements and radicals. This will
help to identify the chemicals.
Chemicals are classified in different ways. For study
(chemistry) point of view, they are broadly classified
as inorganic and organic chemicals. Inorganic chemicals
are subclassified as metals and non-metals. Out of
104 elements, 80 are metals and majority of them (except
mercury) are solids, shining, reflecting, good conductor
and forming reducing agents and basic hydroxides.
In non-metals, more than half are gases and remaining
are hard solid, non-shining, less reflective, bad
conductor and forming oxidising agent and acidic hydroxides.
Some examples are given below :
: Aluminium, Arsenic, Beryllium, Calcium, Chromium,
Cobalt, Copper, Iron, Lead, Manganese, Mercury, Nickel,
Radium, Sodium, Tin, Uranium, Zinc etc.
: Bromine, Chlorine, Fluorine, Iodine, Oxygen, Phosphorous,
Organic chemicals include carbon compounds. They are
subclassified as under -
Compounds (without benzene-rings) : Hydrocarbons,
Halogen derivatives of paraffin, Alcohol, Ethers,
Aldehydes, Ketones, Carboxylic acids and their derivatives,
organic compounds of Nitrogen and Sulphur, Carbohydrates,
Alicyclic compounds etc.
Compounds (with benzene-rings) : Benzene and its derivatives,
Aromatic amines, Diazo compounds, Dyes, Phenols, Aromatic
alcohol, Aromatic aldehydes, Ketones and quinones
and Aromatic carboxylic acids.
Compounds and Polymers (with other-rings) : Furan,
Pyrrole, Thiophene, Pyridine, Quinoline, Isoquinoline,
Alkaloids-coniine, nicotine, Drugs, Hormones, Vitamins,
Enzymes and Polymers - Natural and Synthetic Rubber
like neoprene, butadiene; synthetic fibres like nylon,
orlon, vinyon, terylene, Synthetic plastics and resins
like cellulose, formaldehyde, alkyd, vinyl, acrylate
and polystyrene resins and silicones.
Chemicals are also classified as under :
According to their Physical State i.e. solid, liquid
or gases. Fine particles of solid like powder, dust,
fumes and smoke are called particulate matter. Their
suspension in air or gas also exists. Liquids are
classified as acid, alkali, solvent, suspension, liquid
mixture, aerosols etc. Gases are classified as inert
(N2, CO2), reactive, toxic, irritant, corrosive etc.
2. Noxious Gases :
· Irritant gases - Cl2, NH3, SO2, NO2, COCL2,
· Systemic poisons - C6H6, CS2, PH3, Stibine,
Mn, Nickel carbonyl, Arsine, Halogenated hydrocarbons
· Simple asphyxiates - N2, CH4, CO2 etc.
· Chemical asphyxiates - CO, H2S, HCN etc.
3. Dust (Particulate Matter) :
· Causing plenumoconioses - Coal, Silica, Asbestos
· Causing Asthma - Cotton, Flour, TDI etc.
· Causing allergy - fungal spores, bird fanciers,
lung, bagassation etc.
· Causing lung cancer - Chromium, Asbestos,
4. Biological Agents and Diseases :
· Virus Rickettisia - Psittacosis, rabbis etc.
· Bacteria - Anthrax, Woolsorter's disease,
Leptospirosis or Weal's disease, Brucellosis, Tetanus
· Fungi - Ringworm, Moniliasis etc.
· Parasites - Hookworm
· Plant products - Dermatitis due to mango
tree and cashew seed processing.
For details see the Schedule given under the Rules
for manufacture, use, import, export and storage of
hazardous micro-organism, genetically engineered organism
or cells (Refer Part 2.34 of Chapter-28).
Some physical, chemical or biological agents cause
skin diseases (dermatitis) and alcoholism, sickness
or accident may also cause health effects.
The chemicals should be properly identified, classified
and handled accordingly. Labelling on packages and
containers is a basic requirement. For this purpose
some major divisions are given below :
Corrosive Chemicals : Amyl trichlorosilane, Anisoyl
chloride, Antimony pentachloride, Antimony pentafluoride,
Benzoyl chloride, Benzyl bromide, Benzyl chloride,
Benzyl chloroformate, Boron trichloride, Bromine,
Bromine pentafluoride, Bromine trifluoride, Caustic
potash, Caustic soda, Chloroacetyl chloride, Chlorine
trifluoride, Chlorosulphonic acid, Chromic acid solution,
Diethyl dichlorosilane, Ethyl chloroformate, Formic
acid, Fluorine, Hexafluorophosphoric acid, Hydrazine,
Hydrobromic acid, Hydrochloric acid, Hydrofluoric
acid, Methyl chloroformate, Nitric acid, Perchloric
acid, Oxybromide, Oxychloride, Tribromide, Trichloride
of phosphorous, Tetrachloride, Sodium aluminats, Spent
sulphuric acid, Sulphur chloride (mono and di), Sulphuric
chloride, Thionyl chloride, Titanium tetrachloride,
Oxidising Agent : Aluminium nitrate, Ammonium nitrate,
Ammonium perchlorate, Ammonium permanganate, Barium
chlorate, Barium nitrate, Barium perchlorate, Barium
peroxide, Benzoyl peroxide, Nitrate peroxide, Permanganate
of calcium, Chlorate and Magnesium chloride mixture,
Chlorate of potash and soda, Chromic acid, Dimethyl
hexane, Lead nitrate, Lithium peroxide, nitrate, perchlorate,
Peroxide of magnesium, Potash permanganate, Permanganate
of soda, Potassium bromate, nitrate, nitrite, perchlorate,
permanganate and peroxide, Silver nitrate, chlorate,
chlorite, permanganate, peroxide, and nitrite, Zinc
ammonium nitrite, Zinc chlorate, Zinc permanganate,
Zinc peroxide etc.
Carcinogens : Asbestos, Acrolein, Aniline, Acrylonitrile,
Alpha- Naphthylamine, Beta-Naphthylamine, Benzidine,
Benzene, Benzyl chloride, Carbon tetrachloride, Chloroform,
Chloropropane, Dioxin, Epichlorohydrin, Ethylene oxide,
Formaldehyde, Perchloroethylene, Beta propiolacetone,
Styrene, Tetrachloro ethane, Toluidine (ortho-meta),
Toluenediamine, Trichloroethane, Trichloroethylene,
Vinyl chloride, Pyridine, Phenol, 4-aminodiphenyl,
Poisonous Chemicals : Aldrin mixture, Aniline, Arsenate
of lead, Arsenic acid, Bromide, Chloride, Sulphide
of arsenic, Calcium arsenate, Phenol, Dinitrochlorobenzol,
Cyanide of potassium and sodium, Cyanogen gas, Cyclohexane,
Dinitrophenol, Ethyldichloroarsine, Hexaethyl tetraphosphate,
Hydrocyanic acid and its fumes, Mercuric acetate,
Marcuric ammonium chloride and benzoate, Mercuric
cyanide, bromide, oxide, Iodide, Methyl bromide, Methyl
dichloroarsine, Mustard gas, Nickel cyanide, Nitrobenzol,
Nitrogen peroxide, Phosgene, Thio phosgene, Zinc arsenate,
MIC (methyl iso-cyanate), Carbon monoxide, Cadmium,
DDT, Methanol, Phosphine and dangerous pesticides
such as Parathion, Diazeomon, Tetraethyl pyrophosphate,
Tetraethyl phosphate, Demeton, Scheadan, Methyl parathion,
Cryolite, Pentachlorophenol. Dinitro-o-cresol, Endrin
Explosive Chemicals : Amyl acetate, Carbon dust, Aluminium
dust, Wood saw dust, Hydrogen, Sodium metal, Sodium
nitrate, Potassium nitrate, Ammonium nitrate, Benzoyl
chloride, Nitro glycerine, Phosphorous trichloride,
Titanium powder, Hexane, Trinitro toluene, Carbon
disulphide, Ethylene oxide, Cellulose films etc.
Solvents : Benzene, Acetone, Methanol, Ethanol, Toluene,
Carbon tetrachloride, Methyl chloride, Methylene chloride,
Ethyl acetate, Ethyl ether, Methyl bromide, Nitro
propane, Propyl acetate, Spirit, Petrol, Carbon disulphide,
Ethyl benzene, Methyl-propyl, Turpentine, Chloroform,
Aniline, Benzyl chloride, Bromobenzene, Chlorobenzene,
Ethyl benzene, Ethylamine, Formic acid, Heptane, Glycerol,
Iso Propyl acetate, Methoxy benzene (anisole), Methyloleat,
Naphthalene, Nitrobenzene, Oleic acid, Phenol, Styrene,
Vinyl acetate, Xylene, Ether etc.
Other Flammable Chemicals : Acetonitrile, Acrylonitrile,
Aluminium triethyl, Amyl acetate, Amyl chloride, Amyl
mercaptan, Amyl nitrate, Benzoyl peroxide, Butadiene,
Calcium phosphide, Carbon disulphide, Carbon monoxide,
Coal tar, Naphtha, Lacquer, Paint, Varnish, Diethyl
aluminium chloride, Diethylamine, Dimethylamine, Ethyl
aluminium dichloride, Ethyl chloride, Ethylene, Ethylene
dichloride, Ethylene oxide, Ethyl nitrate, Ethyl nitrite,
Heptane, Hexane, Iso octane, Liquefied Petroleum Gas
(LPG), Lithium metal, Methane, Methyl acetone, Monoethylamine,
Nickel carbonyl, Pentane, Petroleum naphtha, Phosphorous,
Phosphorous anhydride, Photographic film, Sodium aluminium
hydride, Sodium metal, Sodium methylate dry, Titanium
metal powder, Vinyl chloride, Vinyl fluoride, X-ray
film scrap etc.
Reactive Chemicals : Acetic acid, Acetone, Acetylene,
Sodium, Potassium, Lithium, Magnesium, Calcium, Aluminium
powder, Anhydrous ammonia, Ammonium nitrate, Aniline,
Bromine, Chlorates, Chromic acid, Chromium trioxide,
Chlorine, Fluorine, Hydrocarbons (Benzene, Butane,
Propane, Turpentine etc.), Hydrocyanic acid, Hydrofluoric
acid (HF), Hydrogen peroxide, Hydrogen sulfide, Iodine,
Mercury, Nitric acid (Conc.), Oxalic acid, Peroxides,
Phosphorous (white), Potassium chlorate, Potassium
permanganate, Silver, Sodium, Sodium nitrite, Sodium
peroxide, Sulphuric acid etc.
Pesticides - Insecticides :
Pesticides : Aluminium phosphide, aldrin, acephate,
antu, Butachlor, Chlordane, Chlorpyrifos, Cycocel,
Cypermethrin, DDT, Dimethoate, Decamethrin, DDVP,
Dieldrin, Endosulfan, EDB, Formothion, Fenitrothion,
Fenvalerate, Hexachlorobenzene (BHC), Heptachlor,
Glyphosphate, Glyphosine, Malathion, Monocrotophos,
Mercuric acetate, MEMC, 2,4-D Phosphomidone, parathion,
Permethrin, Phenthoate, Phenyl Mercuric acetate, Quinalphos,
Zinc phosphide etc.
Insecticides : Cupric sulfate, DDT, Leadarsenate,
Liver of sulfur.
Fungicides : Bordeaux mixture, Chlornil, Chloropicrin,
Cyprus oxide, Mercurous chloride, Pentachlorophenol.
Herbicides : Ammonium thiocynate NH4SCN
Vermicides : Anisole.
Alcohols : Allyl, ethyl, methyl, emyl, anisyl, benzyl,
butyl, cetyl, citronellol, cyclohexanol, diols or
glycols, lauryl, nerol etc.
Refrigerant Gases : Carbon dioxide CO2, Ammonia NH3,
Esters : Amyl acetate, arsenate, benzoate, borate,
citrate, cynate, decanoate, glyceride, isocyanate,
lipids, methacrylate, nitrite, oxalate, salicylate,
stearate, succinate, sulfate, sulphonate, tertrate,
thiocynate, thiosulphate, toluate, xanthates etc.
Ethers : Anisole (methyl phenyl ether), benzyl cellulose,
thio ethers, RSR, vinyl ether etc.
Enzymes : Catalase, Deaminase, Dehydrogenase, Diastrate,
Fermerit, hydrolases, lactose, oxidase, urease etc.
Resins : Alkyd (glyptal), Allyl, Aminoplastic etc.
Acids : Inorganic : Hydrochloric, hydrobromic, hydrofluoric,
hydroiodic, nitric, sulphuric, nitrous, sulphurous,
sulphonic, chlorosulphonic, boracic or boric, phosphoric,
phosphorous, perchloric, arachidic, arsenic, ascorbic,
aspartic, aspirin, hydrazoic, behenic or docosanoic,
bromic, chloric, chloroplatinic, chlorous, chromic,
iodic, manganic, metaphosphoric, perboric, permanganate,
Organic : Acetic, acrylic, adipic, amino or carboxylic,
alginic, uric, uncleic, succinic, barbituric, benzenesulphonic,
benzoic, capric or decanoic, hexanoic, caprylic or
octanoic, carbolic or phenol, carbonic, carboxylic,
caro's or persulphuric, ricinoleic, chloroacetic,
cinnamic, citric, crotonic or butenoic, cyanic, cyanuric
or tricyanic, ethylene diamine tetraacetic acid (EDTA),
fumaric, galic, gluconic, hexanoic, hydrodic, hydrobromic,
hydrocyanic, hydrofluoric, hydrozy, hypoclorus, hypophosphorous,
isophthalic, lactic, lauric, linolegic, meleic, malic,
malonic, mandelic, methacrylic, molybdic, monobasic,
necotinic, nucleic, octanoic, oleic, oleum, osmic,
oxolic, oxydiacetic, oxydiethanoic, palmitic, pantothenic,
pelargonic, phosphinic, phthalic, picric, pyrophosphoric,
pyrosulphuric, pyruvic, racemic, ribonucleic, ricinoleic
salicylic, sebacic, selenic, silicic, stannic, stearic,
suberic, sulphanilic, fannic, tartaric, thiocyanic,
thiosulphuric, tribasic, trihydroxybenzoic, uric,
Partial List of Incompatible Chemicals (Reactive Hazards)
Substance in the left hand column should be stored
and handled so that they cannot possibly accidentally
contact corresponding substance in the right hand
column under uncontrolled condition because violent
reactions may occur.
Acetic acid Chromic acid, nitric acid, hydroxyl-containing
compound, ethylene, glycol, perchloric acid, peroxide
Acetone Concentrated nitric & sulphuric acid mixtures
Acetylene Chlorine, bromine, copper, silver, fluorine
Alkali and alkaline earth metals such as sodium, potassium,
lithium, magnesium, calcium, powdered aluminium Carbon
dioxide, carbon tetrachloride and other chlorinated
hydrocarbons (also prohibit water foam and dry chemical
on fires involving these metals. Dry sand should be
Ammonia (anhyd.) Mercury, chlorine, calcium hypochlorite,
iodine, bromine and hydrogen fluoride
Ammonium nitrate Acids, metal powders, flammable liquids,
chlorites, nitrites, sulphur, finely divided organics
Aniline Nitric acid, hydrogen peroxide
Bromine Ammonia, acetylene, butadiene, butane and
other petroleum gases, sodium carbide, turpentine,
benzene and finely divided metals
Calcium oxide Water
Carbon, activated Calcium hypochlorite
Chlorates Ammonium salts, acids, metal powder, sulphur,
finely divided organic or combustibles
Chromic acid and Chromium trioxide Acetic acid, naphthalene,
champhor, glycerol, turpentine, alcohol and other
Chlorine Ammonia, acetylene, butadiene, butane and
other petroleum gases, hydrogen, Sodium carbide, turpentine,
benzene and finely divided metals.
Chlorine dioxide Ammonia, methane, phosphine and Hydrogen
Copper Acetylene, Hydrogen peroxide
Fluorine Isolates from everything
Hydrazine Hydrogen peroxide, Nitric acid, any other
Hydrocarbons (benzene, butane, propane, gasoline,
turpentine) Fluorine, chlorine, bromine, Chromic acid,
Hydrocyanic acid Nitric acid, alkalis
Hydrofluoric acid Ammonia
Hydrogen peroxide Copper, chromium, iron, most metals
or their salts, any inflammable liquid, combustible
materials, aniline, nitro methane
Hydrogen sulphide Fuming Nitric acid, oxidising gases
Iodine Acetylene, ammonia
Mercury Acetylene, ammonia, fulminic acid
Nitric acid (Conc.) Acetic acid, acetone, alcohol,
aniline, Chromic acid, Hydrocyanic acid, Hydrogen
sulphide, flammable gases and nitratable substance
Nitroparaffins Inorganic bases, amines
Oxalic acid Silver, mercury
Oxygen Oils, grease, hydrogen, flammable liquids,
solids or gases
Perchloric acid Acetic anhydride, bismuth and its
alloys, alcohol, paper, wood, grease, oils
Peroxides, organic Acids (organic or mineral), avoid
friction, store cold
Phosphorous (white) Air, oxygen
Potassium chlorate Acids
Potassium perchlorate Acids
Potassium permanganate Glycerol, Ethylene glycol,
benzaldehyde, Sulphuric acid
Silver Acetylene, Oxalic acid, Tartaric acid, Ammonium
Sodium nitrite Ammonium nitrite and other Ammonium
Sodium peroxide Any oxidisable substance such as ethanol,
methanol, glacial acetic acid, Acetic anhydride, Benzaldehyde,
Carbon disulphide, Glycerol, Ethylene glycol, Ethyl
acetate, Methyl acetate
Sulphuric acid Chlorate, perchlorates, permanganates
Partial List of Incompatible Chemicals (Toxic Hazards)
Substances in the left hand column should be stored
and handled so that they cannot possibly accidentally
contact corresponding substances in the centre column,
because toxic materials (right hand column) would
Arsenic material Any reducing agent Arsine
Azides Acids Hydrogen azide
Cyanides Acids Hydrogen cyanide
Hypochlorites Acids Chlorine or hypochlorus acids
Nitrates Sulphuric acids Nitrogen dioxide
Nitric acids Copper, brass, any heavy metal Nitrogen
Nitrites Acids Nitrous fumes
Phosphorous Caustic alkalis Phosphine
Selenides Reducing agents Hydrogen selenide
Sulphides Acid Hydrogen sulphide
Tellurides Reducing agents Hydrogen telluride
Material Safety Data Sheet (MSDS)
For proper identification of material hazards a material
safety data sheet should be prepared and supplied
with each chemical so that its safety precautions
can be well understood. A specimen form is given below
1. Chemical Identity :
1. Name of the Chemical
4. Trade name
5. Chemical Classification
6. Regulated identification
7. Shipping Name, Codes/Label
8. CAS No.
9. UN No.
10. ADR No.
11. Hazchem (EAC)No.
12. Hazardous Waste ID No.
13. Hazardous Ingredients and CAS No.
2. Physical & Chemical Data :
1. Appearance, State, Odour etc.
2. Specific gravity (Water = 1)
3. Vapour density (air = 1)
4. Boiling point
5. Melting/Freezing point
6. Vapour pressure
7. Solubility in water
8. Scrubbing/Neutralising/Inactivating media
3. Fire & Explosion Hazard Data :
1. Flash point
2. Autoignition Temperature
3. Flammable limits : LEL/UEL
4. TDG Flammability
5. Explosion Sensitivity to Impact
6. Explosion Sensitivity to static electricity
7. Explosive material
8. Flammable material
9. Combustible and flammable Liquid
10. Pyrophoric material
11. Hazardous Combustion products
12. Hazardous Polymerisation
13. Corrosive material
14. Organic Peroxide
4. Reactivity Data :
1. Chemical stability
2. Incompatibility (Materials to avoid)
4. Hazardous reaction products
5. Health Hazard Data :
1. TLV (ACGIH)
3. LC50 or LD50
4. Odour threshold
5. Carcinogen ? Poison ? Liberates poisonous fume
6. Routes of entry
7. Body parts that may be affected
8. Effects of exposure and symptoms
9. Emergency and first aid treatment
10. Engineering controls necessary for safe handling.
11. NFPA Hazard signals
12. Special Health hazards.
6. Preventive Measures :
1. Ventilation required and type
2. Personal protective equipment required and type
3. Handling and storage precautions
7. Emergency and First-aid Measure :
1. Steps to be taken in case material is released
2. Waste disposal method for solid, liquid and gaseous
3. Fire, extinguishing media, special procedures and
4. Exposure - First-aid measures, Antidotes, Dosages.
8. Additional Information / References :
9. Manufacturer / Supplier's Data :
1. Name of Firm
2. Mailing address
3. Telephone/Telex/Fax Nos.
4. Telegraphic address
5. Contact person in emergency
6. Local bodies involved
7. Standard packing
8. Tremcard Details / Ref.
Interpretation and use of MSDS
the better understanding and use of the Material Safety
Data Sheet, some terms are explained below :
Formula (Chemical) : It is a symbolic representation
of a chemical entity or relationship between elements,
molecule and atoms. e.g. H2 one molecule of hydrogen,
2H2SO4 two molecules of sulphuric acid, H2O one molecule
of water wherein there are two atoms of hydrogen and
one atom of oxygen. C6H6 benzene contains six atoms
of carbons and six atoms of hydrogen in one molecule,
group or ion. Thus by formula we can know the hazardous
ingredient of a chemical.
Synonym : Indicates alternate name of a material.
e.g. Dimethyl ketone or 2-Propanone for Acetone.
Trade Name : Commercial name of the product.
Chemical Classification : General classification is
organic or inorganic. Hazardwise classification can
be flammable, explosive, toxic or poisonous, corrosive,
reactive, infectious, oxidising, radioactive etc.
CAS No. : It is Chemical Abstracts Service number
to provide a single unique identifier with naming
the chemical. e.g. CAS No. for acetic acid is 64-19-7.
It does not indicate the hazards of a material.
UN No. : It is United Nations four digit number assigned
to potentially hazardous material (e.g. Ammonia UN
No. 1005) or Class of material (e.g. corrosive liquids
UN No. 1760).
These numbers are internationally recognised and used
by emergency response personnel (including ire fighters)
to identify material during transport emergencies.
UN, Hazchem, NA and PIN numbers have the same uses.
Hazchem (EAC) No. : Hazchem (hazardous chemical) Code
or EAC (Emergency Action Code) is an emergency code
confirmed by the Health & Safety Executive, UK.
It consists of a number (1 to 4) followed by one or
two letters and signifies type of a fire extinguisher
required, type of personal protective equipment required,
whether the spillage should be contained or diluted
with water, whether the material is reactive and whether
evacuation of the surrounding area necessary. Hazchem
No. of Sodium cyanide is 4X and that of Vinyl chloride
ADR No. : It is an Agreement concerning carriage of
Dangerous goods by Road. This European agreement was
arrived at Geneva by 19 European countries for the
safety of international transport by road. It deals
with the classification of hazardous substances, their
packaging, loading and unloading, transportation and
its equipment. It gives hazard identification numbers
like UN hazard class number. Their comparison is given
of Dangerous Goods by
UN Number ADR Number
1 Explosives. 2 Emission of gas
2 Gases- Compressed, due to pressure or
liquefied, dissolved due to chemical
under pressure or reaction.
deeply refrigerated. 3 Flammability of
3 Flammable liquids. liquids (vapours)
4 Flammable solids. and gases.
5 Oxidising 4 Flammability of
substances or gases.
Organic Peroxides. 5 Oxidising (fire
6 Poisonous (Toxic) or intensifying)
substances. 6 Toxicity.
7 Radioactive 8 Corrosivity.
substances. 9 Risk of sponta-
8 Corrosive neous violent
9 Miscellaneous dangerous substances.
Doubling (repeating) of an ADR digit indicates increase
of that particular hazard. Prefix 'X' indicates that
the substance can dangerously react with water. As
an example ADR HIN (Hazard Identification No.) of
Benzene is 33 (UN No. is 1114 and Hazchem No. is 3WE).
Appearance, State, Odour : Appearance includes colour.
State means physical state - solid, liquid or gas.
Odour indicates smell. Odour threshold is that minimum
level (ppm) where the odour will start. If odour threshold
is lower than the permissible safe limit (e.g. TLV,
STEL, IDLH or LC), the odour indicates the presence
of gas and some safety margin is available to run
away or to take precautionary step. But if it is higher,
the gas becomes toxic or hazardous before its odour
starts and this condition is risky. In that event
a reliable gas detector is useful. Sometimes odour
is added to detect the gas leakage e.g. addition of
mercaptan in domestic LPG. Ability to detect odour
may vary from person to person and may mislead if
the other odorous materials are simultaneously present.
Specific Gravity (water = 1) : It is the ratio of
the density of a material to the density of water
(which is 1 g/cc). Lighter material (Sp. gr. <1,
e.g. benzene 0.88) will float and heavier material
(Sp. gr. >1, e.g. sulphuric acid 1.84) will sink.
This information is useful for spill or fire control.
Vapour Density (air = 1) : It is the vapour weight
per unit volume. In MSDS it is given as the ratio
of the density of a gas or vapour to the density of
air. The air density is 1.293 gm/l, but here it is
considered as 1 for easy comparison of gases. Lighter
gases (Vd<1, e.g. ammonia 0.59) will go up (rise)
in the air and heavier gases (Vd>1, e.g. chlorine
2.49) will come down on the bottom. This information
is useful for ventilation design and evacuation (emergency)
Boiling Point : It is that temperature at which the
material changes from a liquid to a gas. Below this
point the liquid can evaporate to form vapour but
at the BP the change from liquid to vapour is faster.
This increases the vapour concentration and its pressure.
This condition poses higher risk of fire, explosion
Thermal Decomposition Products : If the material decomposes
(breaks down) without boiling, the temperature at
which it decomposes is given with the word 'dec'.
Some of the decomposition products are hazardous.
The thermal decomposition products may be quite different
from the chemicals formed by burning the same material
(hazardous combustion products). Information regarding
thermal decomposition is useful to design ventilation
system where a material may be heated.
Hazardous Decomposition Products : They are formed
when a material decomposes (without heating) because
it is unstable or reacts with common material like
water or air (oxygen). This information is useful
to design storage and handling procedures. For example,
phosgene decomposes into corrosive and toxic fumes
of HCl and CO because of heating or coming into contact
of water or steam. Here HCl and CO are hazardous decomposition
Hazardous Combustion Products : These are the chemicals
which are formed when a material burns. They may be
toxic, flammable, smoke, carbon particles or other
hazards. Their amount varies according to temperature
and oxygen (air) available. They may be different
from the thermal decomposition products. This information
is useful to decide the fire fighting material and
Melting Point : It is that temperature at which a
solid material melts and becomes a liquid. This information
is useful for storage and handling purpose. A melted
material may distort a container.
Freezing Point : It is that temperature at which a
liquid material freezes and becomes solid. This information
is useful for storage and handling purpose. A frozen
material may burst a container.
Vapour Pressure : It is the pressure (mm of Hg) upon
atmosphere of the vapour of a material at a fixed
temperature (e.g. 20 0C). Higher vapour pressure indicates
higher concentration and therefore higher hazard due
to fire or inhalation.
Solubility : It is the ability of a material to dissolve
in water or another liquid (solvent). It may be expressed
as a ratio or described by words like insoluble, very
soluble, sparingly soluble or miscible. This information
is useful to decide a scrubbing media, spill control
or fire fighting material and procedure. Such solvent
should not be hazardous.
Scrubbing neutralising or inactivating media : These
are those materials (liquids) which dissolve or react
with the hazardous material (gas, liquid or solid)
to diminish its hazardous exposure e.g. caustic, lime,
water etc. If this is not possible, proper absorbent
may be used e.g. sand, sponge rubber etc.
See Part 8.5 and Table 18.6 of this Chapter and Table-17
of Chapter-32 for scrubbers.
pH : It is a measure of the acidity or alkalinity
(basicity) of a material when dissolved in water.
It is expressed in a scale from 0 to 14 as under :
0 - 2 Strong acidic
3 - 5 Weak acidic
6 - 8 Neutral
9 - 11 Weak basic
12 - 14 Strong basic
This information is useful to select a neutralising
material for scrubbing or effluent treatment or spill
Flash Point : It is the lowest temperature at which
a material gives off enough vapour near its surface
to form a flammable air vapour (gas) mixture so that
it can be ignited if a spark is available. The lower
flesh point indicates higher hazard as it can cause
fire at a lower temperature. It is expressed as Closed
Cup (CC) or Open Cup (OC). CC value is slightly less
than the OC value.
Autoignition Temperature : It is the lowest temperature
at which a material begins to burn in air without
any contact of spark or flame. During heating if the
material decomposes, the decomposed chemical may auto-ignite
at some other temperature. Different test methods
give different auto-ignition temperatures for the
same material. Therefore this value is an estimate.
The material should be stored, processed or handled
well below its auto-ignition temperature to avoid
the risk of self fire or explosion.
Substances liable to spontaneous combustion are those
liable to spontaneous heating under normal conditions
or to heating up on contact with air and being then
liable to catch fire.
Flammable or Explosive Limits (LEL/UEL) : The lowest
concentration (percentage in air) of gas or vapour
which will burn or explode if ignited, is called the
Lower Explosive (or Flammable) Limit i.e. LEL or LFL.
The upper concentration (percentage in air) of gas
or vapour which will burn or explode if ignited, is
called the Upper Explosive (or Flammable) Limit i.e.
UEL or UFL. The range between LEL and UEL is called
the Explosive (or Flammable) Range. The fire or explosion
risk lies within this range but not out of it. Below
LEL the gas-air mixture is too lean to ignite and
above UEL it is too rich to ignite.
However the concentration above UEL should be considered
dangerous as due to entrainment of fresh air, it may
be diluted and enter the explosive range. Similarly
after LEL if gas discharge is continued in the same
air, it can also enter the explosive range. Thus explosive
range can be reached depending on flow of gas and
air affecting their concentration. Air and gas temperature
may also affect. Therefore the range should be considered
as approximate values. For gas/vapour it is expressed
in % of air (1% = 10,000 ppm) and for powder in gm/m3
This information is useful to avoid the conditions
leading to the explosive range and to ascertain it
before allowing any person to enter any vessel or
confined space where such air-gas mixture is suspected.
Explosimeters are available to detect this range.
Detection should be of percentage of LEL and all safety
devices (alarms, controls, trips etc.) should operate
well below the LEL. Fire hazard should be prevented
at pre-determined percentage of LEL.
TDG Flammability : Transport of Dangerous Goods (TDG)
classifies the materials according to their flammability
as under -
3 Flammable liquid (Subclasses 3.1, 3.2 and 3.3 based
on flash point).
4.1 Flammable solid.
4.2 Spontaneously combustible material.
4.3 Material which gives off a flammable gas on contact
Explosion Data (Sensitivity) : It gives explosive
properties of a material e.g. low, moderate or high.
It gives two types of sensitivity :
Sensitivity to Impact - It indicates whether or not
the material will burn or explode on shock or friction,
Sensitivity to Static Electricity - It indicates how
readily the material can be ignited by an electric
spark or static discharge.
Explosive Material : An explosive material is that
material which can explode on impact or by electric
spark. Schedule-1 of Manufacture, Storage and Import
of Hazardous Chemicals Rules, 1989 defines 'Explosives'
as those chemicals which explode under the effect
of flame, heat or photo-chemical conditions or which
are more sensitive to shocks or friction than dinitrobenzene
(old definition) or pyrotechnic substance (firework)
or which is capable of producing gas at such temperature,
pressure and speed to cause damage to surroundings
or exothermic reaction by heat, light, sound, gas,
smoke or their combination (new definition).
Combustible and Flammable Material : Flammable solid,
liquid or gas which can catch fire and burn rapidly
or explosively are flammable materials.
The terms combustible and flammable both indicates
the ability of a material to burn. Any material that
will burn at any temperature is combustible by definition.
Flammable are a special group of combustible materials
that ignite easily and burn rapidly. For example,
NaCl, CCl4 and CO2 are non-combustible while sugar,
cellulose and ammonia are combustible but non-flammable.
The more readily ignition occurs, the more flammable
the material, less easily ignited materials are said
to be combustible, but the line of demarcation is
difficult to decide.
Normally combustible liquids are classified as those
whose flash point is greater than 37.70C (100 0F).
Flammable or Inflammable liquids are classified under
MSIHC Rules as (1) Extremely flammable - having FP<230C
and BP<350C (2) Very highly flammable liquids -
having FP<230C and BP>350C (3) Highly flammable
- having FP between 230C and 600C and (4) Flammable
- having flash point between 600C and 900C.
Thus liquids having flash point between 37.70C to
900C can be called combustible as well as flammable,
while those having flash point greater than 900C should
be called combustible.
Flammable liquids are extremely hazardous, as they
give off vapours at low temperature and these vapours
by travelling to a source of ignition can cause flash
back to the flammable liquid. It is difficult to extinguish
a burning flammable liquid with water because water
may not be able to cool the liquid below its flash
Flammable gases (normally boiling point < 20 0C)
are equally hazardous as flammable vapours as explained
above. Confined flammable gases are most dangerous.
Flammable gases are also defined as those which at
200C and at standard pressure of 101.3 KPa, have LEL
13% or less or a flammable range of 12% or more regardless
of the LEL.
Flammable solids can be ignited due to external heat,
flame, process heating by interaction with water or
other substances. Flammable solids are of various
types (1) Dusts or fine powders e.g. cellulose, flour
etc. (2) Spontaneously ignitable at low temperature
e.g. yellow phosphorous (3) Those in which internal
heat is built-up by microbial or other degradation
activity e.g. fish meal, wet cellulosic material (4)
Films, fibres and fabrics of low-ignition point materials.
Flammable solids are readily combustible or may cause
or contribute to fire through friction or which are
liable to undergo a strong exothermic reaction.
Corrosive Material : It can attack (corrode) metals
or human tissues such as skin or eyes. Structure or
metal container may become weak and eventually collapse
or leak. Skin, eyes or other body parts can be badly
affected (burning) by corrosive materials. Acids,
halogen gases, chlorides, caustic, phenol etc. are
Hazardous Polymerisation : A polymer is a natural
or man-made material formed by combining units called
monomers, into long chains. e.g. styrene is the monomer
Polymerisation is the process of forming a polymer
by combining monomers into long chains. Uncontrolled
polymerisation can be hazardous, as it can cause heat,
pressure or explosion. Some chemicals can polymerise
on their own without warming, others upon contact
with water, air or common chemicals. Vinyl chloride
rapidly polymerises in presence of light, air or heat.
Therefore polymerising conditions should be controlled
properly. Inhibitors(negative catalysts or compounds
that retard or stop an undesired chemical reaction
such as polymerisation, oxidation, corrosion etc.)
are normally added to products to reduce or eliminate
the possibility of hazardous polymerisation.
Pyrophoric Material : Any liquid or solid that will
ignite spontaneously in air at about 54.4 0C (130
0F). Titanium dichloride and phosphorous are examples
of pyrophoric solids, tributylaluminium and related
compounds are pyrophoric liquids. Sodium, butyllithium
and lithium hydride are spontaneously flammable in
moist air as they react exothermically with water.
Such materials must be stored in inert gas or under
kerosene. Some alloys (barium, misch metal) are called
pyrophoric because they spark when slight friction
Pyrotechnic materials mean fireworks.
Catalysts of pyrophoric material which can burn in
normal air, are replaced in the atmosphere of nitrogen
blanketing. The workers have to wear self-breathing
apparatus while doing such job, because in the atmosphere
of about 90% nitrogen, oxygen is insufficient for
Oxidiser and Peroxide : It is a compound that spontaneously
evolves oxygen either at room temperature or under
slight heating. Oxidisers include peroxides, chlorates,
perchlorates, nitrates and permanganates. These can
react vigorously at ambient temperatures when stored
near or in contact with reducing materials (that will
remove oxygen or add hydrogen) such as cellulosic
and other organic compounds. Storage areas should
be well ventilated and kept as cool as possible.
Peroxides release atomic (nascent) oxygen readily.
They pose fire hazards in contact with combustible
materials, especially under high temperature conditions.
They are used as oxidising agents, bleaching agents
and initiators of polymerisation.
Oxidizing substances are not necessarily combustible
in themselves but by giving oxygen they contribute
to combustion of other materials.
Organic Peroxides contain bivalent 0-0-structure,
are thermally unstable and may undergo exothermic
Chemical Stability : A stable compound does not easily
decompose or react readily. Chemical stability is
the ability of a material to remain unchanged in the
presence of heat, moisture or air. An unstable compound
may decompose, polymerise, burn or explode under normal
environmental conditions. Special precautions are
required to store or handle unstable materials. For
examples, CS2 decomposes in light and burns due to
heat, spark, flame or friction and gives off toxic
fumes of SOx. Caprolectum liberates NOx fumes due
to heating. TNT explodes due to heavy shock or by
heating. Thus conditions disturbing stability must
Incompatibility : Compatibility means the ability
of two or more materials to exist in close and permanent
association indefinitely. Liquids and solids are compatible
if the solid is soluble in the liquid. Water is compatible
with alcohol (because it is miscible) but not with
gasoline (e.g. petrol).
Incompatibility means disability to co-exist permanently.
Therefore incompatible materials should not be stored
or kept together. For example, toluene reacts violently
with some acids, plastic or rubber, therefore, these
substances should be kept away.
Incompatible materials can cause a fire, explosion,
toxic release, violent reaction, polymerisation or
destroy the structure or function of a product. This
information is useful for storage and handling purposes.
Reactivity : Two or more chemicals can react with
each other and give reaction products. e.g. 2H2 +
O2 = 2H2O. A single chemical can react with air or
water (which are also chemicals) and give the product.
e.g. phosphorous burns in air and gives its oxides
(P2O3, P2O5), sulphur burns and gives SO2 etc.
Reactions are exothermic when they evolve heat and
are endothermic when they need heat to maintain them.
A reversible reaction is one in which the reaction
product is unstable and goes back to the original
In MSDS we are concerned with the hazardous reaction
or reactive material which can cause fire, explosion,
toxic release or violent reaction with air, water
or common chemicals or under environmental conditions.
Phosphorous, CS2, Sodium metal, acids (reactive with
metals) etc. are known for their reactivity. This
information is useful for storage, handling and process
Hazardous Reaction Products : These must be known
for the safety of process, workers and environment.
Here products are more important than the reaction
because of their hazardous nature. e.g. Chlorine reacts
with alcohol and forms explosive alkyl hypochlorite.
If toxic fumes are to be generated, scrubbers are
required, if flammable vapours are generated, inert
gas blanketing is required and earthing of the vessel
also becomes necessary. If reaction products are highly
poisonous like NaCN, HCN etc., they are to be handled
in a closed system.
Health Hazard Data : For TLV, STEL, IDLH, LD/LC etc.
see Part 6.8, for routes of entry see Part 6.6, for
effects of exposure see Part 6.7, for engineering
controls see Part 6.12.2 and for health hazards see
Part 6.1, all of Chapter-24.
For emergency and first aid treatment and antidotes
see Chapter-26, for fire and NFPA (National Fire Protection
Association of USA) Code see Part 4.4 of Chapter-13,
for ventilation see Chapter 10 and for personal protective
equipment see Chapter-25.
TLV and STEL are given in 2nd Schedule of the Factories
Act. LD50 and LC50 are given in 1st Schedule of the
MSIHC Rules for the purpose of major accident hazard.
LD50 for insecticides are given in Rule 19 of the
Insecticide Rules for labelling purpose. Lower these
values, higher the toxicity. LD50 up to 200 mg/kg
and LC50 up to 10 mg/l can cause major hazard. By
local exhaust ventilation toxic gas, dust or vapour
must be captured and effective PPE must be worn by
the workers. Above STEL, SBA is desirable.
Tremcard : Transport Emergency Cards are to be given
to the drivers carrying dangerous goods for emergency
information which may be needed at any time during
journey. The cards contain short information on nature
of chemical, hazards involved, protective devices,
emergency action for fire, spillage, leakage, first-aid