Factories Act, 1948
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. | Acrylo nitrile -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 ( methylethyl Ketone -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 isocyanate ketone | 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. | Sulphur hexaflouride | 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 respirableQuartz +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 |
