Schedule II : Permissible Levels of Certain Chemical Substances in Work Environment
[Section 41F]
S. No | Substance | Permissible limits of exposure | |||
Time-weighted average Concentration (8hrs)M | Short-term exposure limit (15min)* | ||||
ppm | mg/m3** | ppm | mg/m3** | ||
1 | 2 | 3 | 4 | 5 | 6 |
1. | Acetaldehyde | 100 | 180 | 150 | 270 |
2. | Acetic acid | 10 | 25 | 15 | 37 |
3. | Acetone | 750 | 1780 | 1000 | 2375 |
4. | Acrolein | 0.1 | 0.25 | 0.3 | 0.8 |
5. | Acrylonitrile-Skin | 2 | 4.5 | - | - |
6. | Aldrin-skin | - | 0.25 | - | - |
7. | Allylchloride | 1 | 3 | 2 | 6 |
8. | Ammonia | 25 | 18 | 35 | 27 |
9. | Aniline-Skin | 2 | 10 | - | - |
10. | Anisidine (o-p-isomers) Skin | 0.1 | 0.5 | - | - |
11. | Arsenic and Soluble com- pounds (as) | - | 0.2 | - | - |
12. | Benzene(S.C.) | 10 | 30 | - | - |
13. | Beryllium and Compound (as Be) (S.C.) | - | 0.002 | - | - |
14. | Boron trifluoride-C | 1 | 3 | - | - |
15. | Bromine | 0.1 | 0.7 | 0.3 | 2 |
16. | Butane | 800 | 1900 | - | - |
17. | 2-Butane (methylethylKetone-MEK) | 200 | 590 | 300 | 835 |
18. | n-Butyl acetate | 150 | 710 | 200 | 950 |
19. | n-Butyl alcohol-Skin-C | 50 | 150 | - | - |
20. | Sec./tert.Butyl acetate | 200 | 950 | - | - |
21. | Butyl mercaptan | 0.5 | 1.5 | - | - |
22 | Cadmium dusts and salts (as Cd) | - | 0.05 | - | - |
23. | Calcium oxide | - | 2 | - | - |
24. | Carbaryl (Sevin) | - | 5 | - | - |
25. | Carbofuran (Furadan) | - | 0.1 | - | - |
26. | Carbon disulphide-Skin | 10 | 30 | - | - |
27. | Carbon monoxide | 50 | 55 | 400 | 440 |
28. | Carbon tetrachloride – Skin (S.C) | 5 | 30 | - | - |
29. | Chlordene-Skin | - | 0.5 | - | 2 |
30. | Chlorine | 1 | 3 | 3 | 9 |
31. | Chlorobenzene (Monochloro benzene) | 75 | 350 | - | - |
32. | Chloroform (S.C.) | 10 | 50 | - | - |
33. | bis (Chloromethyl) ether (H.C.) | 0.001 | 0.005 | - | - |
34. | Chromic acid and chromates (as Cr.) | - | 0.05 | - | - |
35. | Chromous salts (as Cr) | - | 0.5 | - | - |
36. | Copper Fume | - | 0.2 | - | |
37. | Cotton dust, raw* | - | 0.2* | - | - |
38 | Creosol, all isomers - Skin | 5 | 22 | - | - |
39. | Cyanides (as CN)-Skin | - | 5 | - | - |
40. | Cyanogen | - | 10 | 20 | - |
41. | DDT (Dichlorodi phenyl trichloroethane) | - | 1 | - | - |
42. | Demeton-Skin | 0.01 | 0.1 | - | - |
43. | Diazinon-Skin | - | 0.1 | - | - |
44. | Dibutyl phthalate | - | 5 | - | - |
45. | Dicholorvos (DDVP)-Skin | 0.1 | 1 | - | - |
46. | Dieldrin-Skin | - | 0.25 | - | - |
47. | Dinitrobenzene (all isomers)-Skin | 0.15 | 1 | - | - |
48. | Dinitrotoluene-Skin | - | 1.5 | - | - |
49. | Diphenyl-(Biphenyl) | 0.2 | 1.5 | - | - |
50. | Endosulfan (Thiodan)-Skin | - | 0.1 | - | - |
51. | Endrin-Skin | - | 0.1 | - | - |
52. | Ethylacetate | 400 | 1400 | - | - |
53. | Ethyl alcohol | 1000 | 1900 | - | - |
54. | Ethylamine | 10 | 18 | - | - |
55. | Fluorides (as F) | - | 2.5 | - | - |
56. | Fluorine | 1 | 2 | 2 | 4 |
57. | Formaldehyde (S.C.) | 1.0 | 1.5 | 2 | 3 |
58. | Formic acid | 5 | 9 | - | - |
59. | Gasoline | 300 | 900 | 500 | 1500 |
60. | Hydrazine-Skin (S.C.) | 0.1 | 0.1 | - | - |
61. | Hydrogen Chloride-C | 5 | 7 | - | - |
62. | Hydrogen Cyanide-Skin-C | 10 | 10 | - | - |
63. | Hydrogen flouride (as F)-C | 3 | 2.5 | - | - |
64. | Hydrogen peroxide | 1 | 1.5 | - | - |
65. | Hydrogen sulphide | 10 | 14 | 15 | 21 |
66. | Iodine -C | 0.1 | 1 | - | - |
67. | Iron oxide fume (Fe2O3)(as Fe) | - | 5 | - | - |
68. | Isoamyl acetate | 100 | 525 | - | - |
69. | Isomyl alcohol | 100 | 360 | 125 | 4500 |
70. | Isobutyl alcohol | 50 | 150 | - | - |
71. | Lead, inorg Dusts, dusts and fumes (as Pb). | - | 0.15 | - | - |
72. | Lindane-Skin | - | 0.5 | - | - |
73. | Malathion Skin | - | 10 | - | - |
74. | Manganese (as Mn ) dust and compounds-C | - | 5 | - | - |
75. | Manganese fume (as Mn) | - | 1 | - | 3 |
76. | Mercury (as Hg)-Skin- (i) Alkyl compounds (ii) All forms except alkyl vapor | - - | 0.01 0.05 | - - | 0.03 - |
77. | Aryl and inorganic compounds | - | 0.1 | - | - |
78. | Methyl alcohol (Methanol)-Skin | 200 | 260 | 250 | 310 |
79. | Methyl Cellosolve (2-Methoxy ethanol)-Skin | 5 | 16 | - | - |
80. | Methyl isobutyl ketone | 50 | 205 | 75 | 300 |
81. | Methyl isocyanateketone | 0.02 | 0.05 | - | - |
82. | Naphthalene | 10 | 50 | 15 | 75 |
83. | Nickel carbonyl (as Ni) | 0.05 | 0.35 | - | - |
84. | Nitric acid | 2 | 5 | 4 | 10 |
85. | Nitric oxide | 25 | 30 | - | - |
86. | Nitrobenzene-Skin | 1 | 5 | - | - |
87. | Nitrogen dioxide | 3 | 6 | 5 | 10 |
88. | Oil mist-mineral | - | 5 | - | 10 |
89. | Ozone | 0.1 | 0.2 | 0.3 | 0.6 |
90. | Parathion-Skin | - | 0.1 | - | - |
91. | Phenol-Skin | 5 | 19 | - | - |
92. | Phorate (Thimet)-Skin | - | 0.05 | - | 0.2 |
93. | Phosgene (Carbonyl chloride) | 0.1 | 0.4 | - | - |
94. | Phosphine | 0.3 | 0.4 | 1 | 1 |
95. | Phosphoric acid | - | 1 | - | 3 |
96. | Phosphorus (yellow) | - | 0.1 | - | - |
97. | Phosphorus pentachloride | 0.1 | 1 | - | - |
98. | Phosphorus trichloride | 0.2 | 1.5 | 0.5 | 3 |
99. | Picric acid - Skin | - | 0.1 | - | 0.3 |
100. | Pyridine | 5 | 15 | - | - |
101. | Silane (Silicon tetrahydride) | 5 | 7 | - | - |
102. | Sodium Hydroxide-C | - | 2 | - | - |
103. | Styrene, monomer (Phenyl-ethylene) | 50 | 215 | 100 | 425 |
104. | Sulphur dioxide | 2 | 5 | 5 | 10 |
105. | Sulphurhexaflouride | 1000 | 6000 | - | - |
106. | Sulphuric acid | - | 1 | - | - |
107. | Tetraethyl lead (as Pb)-Skin | - | 0.1 | - | - |
108. | Toluene (Toluol) | 100 | 375 | 150 | 560 |
109. | o-Toluidine-Skin(S.C) | 2 | 9 | - | - |
110. | Tributyl phosphate | 0.2 | 2.5 | - | - |
111. | Trichloro-ethylene | 50 | 270 | 200 | 1080 |
112. | Uranium, natural (as U) | - | 0.2 | - | 0.6 |
113. | Vinyl chloride (H.C.) | 5 | 10 | - | - |
114. | Welding fumes | - | 5 | - | - |
115. | Xylene (o,m,p-isomers) | 100 | 435 | 150 | 655 |
116. | Zinc oxide (i) Fume (ii) Dust (Total dust) | - - | 5 10 | - - | 10 - |
117. | Zirconium compounds (as Zr) | - | 5 | - | 10 |
ppm 3 Parts of vapor or gas per million parts of contaminated air by volume at 25oC and 760 torr. (mm of mercury)
Mg/ m2 milligrams of substance per cubic meter of air.
* Not more than 4 times a day with at least 60 min. interval between successive exposures.
** mg/ m3 = Molecular weight * ppm
24.45
C Denotes ceiling limit.
Skin denotes potential contribution to the overall exposure by the cutaneous route including mucous membranes and eye.
S.C. denotes suspected human carcinogens.
H.C. denotes confirmed human carcinogens.
Substances | SPermissible time-weighted average concentration (TWA) (8 hours) |
Silica, SiO2 | |
(a) Crystalline | |
(i) Quartz | |
(1) In terms of dusts count | 10600 mppcm % Quartz +10 |
(2) In terms of respirable dust | 10 mg/ m2 respirable Quartz +2 |
(3) In terms of total dust | 30 mg/ m2 % 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) Tripoli | Same limit as in formula in item (2) given against quartz |
(b) Amorphous silicate | 10mg/ m3,total dust |
Asbestos (H.C.) | *2 fibers/ ml, greater than 5 um in length and less than 3 um in breadth. |
Portland cement | 10 mg/ m3, total dust containing less than 1% quartz. |
Coal dust | 2 mg/ m3, respirable dust fraction containing less than 5% quartz |
mppcm = Million particles per cubic meter of air, based on impinger samples counted by light-field techniques. *As determined by the membrane filter method at 400 -
450 x magnification (4 mm objective ) phase contrast illumination.
Respirable Dust:
Fraction passing a size-selector with the following characteristics:
Aerodynamic Diameter (um) (Unit density sphere) | % passing selector |
< 2 | 90 |
2.5 | 75 |
3.5 | 50 |
5.0 | 25 |
10 | 0 |