PERMISSIBLE LEVELS OF CERTAIN CHEMICAL SUBSTANCES IN WORK ENVIRONMENT
Substance
Permissible limits of exposure
Time-weighted
average concentration
(8 hrs)
Short-term
exposure limit
(15 min)
ppm Mg/m3 ppm Mg/m3
Acetaldehyde 100 180 150 270
Acetic acid 10 25 15 37
Acetone 750 1780 1000 2375
Acrolein 0.1 0.25 0.3 0.8
Acrylonitrile-Skin (S.C.) 2 4.5 . . . .
Aldrin-skin . . 0.25 . . 0.75
Allychloride 1 3 2 6
Ammonia 25 18 35 27
Aniline-Skin 2 10 . . . .
Anisidine (o-,p-isomers) Skin 0.1 0.5 . . . .
Arsenic A soluble compounds (as As) . . 0.2 . . . .
Benzene (S.C.) 05 1.5 25 7.5
Beryllium & Compound (as Be) (S.C.) . . 0.002 . . . .
Boron trifluoride-C 1 3 . . . .
Bromine 0.1 0.7 0.3 2
Butane 800 1900 . . . .
2-Butanone (Methyl-ethyl Ketone-MEK) 200 590 300 835
n-Butyl acetate 150 710 200 950
n-Butyle alcohol-Skin-C 50 150 . . . .
sec/tert. Butylacetate 200 950 . . . .
Butyl mercaptan 0.5 1.5 . . . .
Cadmium Dusts and salts (as Cd) . . 0.05 . . . .
Calcium oxide . . 2 . . . .
Carbaryl (Sevin) . . 5 . . . .
Carbofuran (Furadan) . . 0.1 . . . .
Carbon disulphade-Skin 10 30 . . . .
59
ppm Mg/m3 ppm Mg/m3
Carbon monoxide 50 55 400 440
Carbon tetrachloride-Skin (S.C.) 5 30 . . . .
Chlordane-Skin . . 0.5 . . . .
Chlorine 1 3 3 9
Chlorobenzene (Monochlorobenzene) 75 350 . . . .
Chloroform (S.C.) 10 50 . . . .
bis (Chloromethyl) ether (H.C.) 0.001 0.005 . . . .
Chromic acid and chromates (as Cr) (Water Soluble) . . 0.05 . . . .
Chromous salts (as Cr) . . 0.05 . . . .
Copper Fume . . 0.2 . . . .
Cotton dust, raw . . 0.2 . . 0.6
Crosol, all isomers—Skin 5 22 . . . .
Cyanides (as CN)—Skin . . 5
. . . .
Cyanogen 10 20 . . . .
DDT (Dichlorodiphenyltrichloroethane) . . 1
. . 3
demeron-Skin 0.01 0.1 0.03 0.3
Diazinon-Skin . . 0.1 . . 0.3
Dibutylphthalale . . 5
. . 10
Dichlorvos (DDVP)—Skin 0.1 1
0.3 3
Dieldrin—Skin . . 0.25 . . 0.75
Dinitrobenzene (all isomers)—Skin 0.15 1
0.5 3
Dinitrotolune-Skin . . 1.5 . . 5
Diphenyl-(Biphenyl) 0.2 1.5 0.6 4
Endosulfan (Thiodan)—Skin . . 0.1 . .
0.4
Endrin—Skin . . 0.1 . .
0.3
Ethyl acetate 400 1400 . .
. .
Ethyl alcohol 1000 1900 . .
. .
Ethylamine 10 18 . .
. .
Fluorides (as F) . . 2.5 . .
. .
Fluorine 1 2 2 4
Formaldehyde (S.C.) 1.0 1.5 2 3
Formic acid 5 9 . . . .
Gasoline 300 900 500 1500
Hydrazine—Skin (S.C.) 0.1 0.1 . . . .
Hydrogen chloride—C 5 7 . . . .
60
ppm Mg/m3 ppm Mg/m3
Hydrogen cyanide—Skin—C 10 10 . . . .
Hydrogen fluoride (as F)—C 3 2.5 . . . .
Hydrogen peroxide 1 1.5 . . . .
Hydrogen sulphide 10 14 15 21
Iodine—C 0.1 1 . . . .
Iron-Oxide Fume (Fe2O3) (as Fe) . . 5 . . . .
Isoamyl acetate 100 525 . . . .
Isoamyl alcohol 100 360 125 4500
Isobutyl alcohal 50 150 . . . .
Lead, inorg, dusts and fumes (as Pb) . . 0.15 . . . .
Lindane-Skin . . 0.5 . . . .
Malathion-Skin . . 10 . . . .
Manganese dust and compounds (as Mn)—C . . 5 . . . .
Manganese fume (as Mn) . . 1 . . 3
Mercury (as Hg)—Skin—
(i) Alkyl compounds . . 0.01 . . 0.03
(ii) All forms except alkyl vapour . . 0.05 . . . .
(iii) Aryl and inorganic compounds . . 0.1 . . . .
Methyl alcohol (Methanol)—Skin 200 260 250 310
Methyl Cellosolve (2-Methoxy-ethanol) Skin 5 16 . . . .
Methyl isobutyl ketone 50 205 75 300
Methyl isocyanate-Skin 0.02 0.05 . . . .
Napthalene 10 50 15 75
Nickel carbonyl (as Ni) 0.05 0.35 . . . .
Nitric acid 2 5 4 10
Nitric oxide 25 30 . . . .
Nitrobenzene—Skin 1 5
. . . .
Nitrogen dioxide 3 6 5 10
Oil mist-mineral . . 5 . . 10
Ozone 0.1 0.2 0.3 0.6
Parathion—Skin . . 0.1 . . . .
Phenol—Skin 5 19 . . . .
Phorate (Thimet)—Skin . . 0.05 . . 0.2
Phosgene (Carbonyl chloride) 0.1 0.4 . . . .
Phosphine 0.3 0.4 1 1
61
ppm Mg/m3 ppm Mg/m3
Phosphoric acid . . 1 . . 3
Phosphorus (yellow) . . 0.1 . . . .
Phosphorus pentachloride 0.1 1 . . . .
Phosphorus trichloride 0.2 1.5 0.5 3
Picric acid—Skin . . 0.1 . . 0.3
Pyridine 5 15 . . . .
Silane (Silicon tetrahydride) 5 7
. . . .
Sodium hydroxide—C . . 2
. . . .
Styrene, monomer (Phenylethylene) 50 215 100 425
Sulphur dioxide 2 5 5 10
Sulphur hexafluoride 1000 6000 . . . .
Sulphuric acid . . 1 . . . .
Tetraethyl lead (as Pb)—Skin . .
0.1 . .
. .
Toluene (Toluol) 100 375 150 560
O—Toluidinz—Skin (S.C.) 2 9 . . . .
Tributyl phosphate 0.2 2.5 . . . .
Trichloroethylene 50 270 200 1080
Uranium, natural (as U) . . 0.2 . . 0.6
Vinyl chloride (H.C.) 5 10 . . . .
Welding fumes . . 5 . . . .
Xylene (o-, m-, p-isomers) 100 435 150 655
Zinc oxide—
(i) Fume . . 5.0 . . 10
(ii) Dust (Total dust) . . 10.0 . . . .
Zirconium compounds (as Zr) . . 5 . . 10
C denotes ceiling limit
*Not more than 4 times a day with at least 60 min. interval between successive exposures.
Substance Permissible
(8 hours)
Timeweighted
average concentration
(i) Silica
(a) Crystalline
(b) Quartz
(1) In term of dusts count 10600
mppcm
% Quartz+10
62
Substance Permissible
(8 hours)
Timeweighted
average concentration
(2) In terms of respirable dust
(3) In terms of total dust
10 mg/m3
% respirable quartz+2
10 mg/m3
% Quartz+3
(ii) Cristobalite Half the limits given against quartz.
(iii) Tridymite Half the limits given against quartz.
(iv) Silica, fused Same limits as for quartz.
(v) (a) Tripoli Same limit as in formula in item 2 given against
quartz.
(b) Amorphous 705 mppcm.]