Schedule XXXVII

{see sub-rule (1) of rule 124}

Permissible levels of certain chemical substances in work environment

Permissible limits of exposure

Time weighted average Short-term

Substance concentration exposure limit

(8 hrs) (15 min)*

Sl. No. ppm mg/m3** ppm mg/m3**

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. Allyl Chloride 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 & compounds (as As) -- 0.2 -- --

12. Benzene(H.C.) 10 20 25 7.5

13. Beryllium & Compound (as Be) (S.C.) -- 0.002 -- --

14. Bornon Trifluoride-C 1 3 -- --

15. Bromine 0.1 0.7 0.3 2

16. Butane 800 1900 -- --

17. 2-Butanon (Methyl-ethyl Ketone MBK) 200 590 300 885

18. n-Butyl acetate 150 710 200 950

19. n-Butyl alcohol-skin-C 50 150 -- --

20. Sce/tert, Butyl acetate 200 950 -- --

21. Butyl Mercaptan 0.5 1.5 -- --

22. Cadmium-dust 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. Carbonate trachloride-skin 5 30 -- --

29. Carbonyl Chloride (Phosgene) 0.1 0.4 -- --

30. Chlorobenzene (monochloro-benzene) 75 350 -- --

31. Chloridane-skin -- 0.5 -- --

32. Chlorine 1 3 3 9

33. Chloroform (S.C.) 10 50 -- --

34. bis-(Chloromethyl) ether (H.C.) 0.001 0.005 --

35. Chromic acid and chromates (as Cr) -- 0.05 -- --

water soluble

36. Chromous Salts (as Cr) 0 05 -- --

37. Copper fume -- 0.2 -- --

38. Cotton dust, raw -- 0.2 -- --

39. Cresol, all isomers-skin 5 22 -- --

40. Cyanides (as CN)-skin -- 5 -- --

41. Cyanogen 10 20 -- --

42. DDT(Dichloro diphenyl -- 1 -- --

trichloroethane)

43. Demeron-skin 0.01 0.1 -- --

44. Diazinon-skin -- 0.1 -- --

45. Dibutyl pythalate -- 5 -- --

46. Dichiorvos (DDVP)-skin 0.1 1 -- --

47. Dieldrin-skin -- 0.25 -- --

48. Dinitrobenzene, (all isomers )- skin 0.15 1 -- --

49. Dinitrotoluene-skin -- 1.5 -- --

50. Diophenyl (Biphenyl) 0.2 1.5 -- --

51. Endosulfan (Thiadon)-skin -- 0.1 -- --

52. Endrin-skin -- 0.1 -- 0.3

53. Ethyl acetate 400 1400 -- --

54. Ethyl alcohol 1000 1900 -- --

55. Ethylamin 10 18 -- --

56. Fluorides (as F) -- 2.5 -- --

57. Fluorine 1 2 2 4

58. Formic Acid 5 9 -- --

59. Hydrazine-skin (S.C.) 0.1 0.1 -- --

60. Hydrogen Chloride-C 5 7 -- --

61. Hydrogen Cyanide-skin-C 10 10 -- --

62. Hydrogen fluoride (as F)-C 3 2.5 -- --

63. Hydrogen Peroxide 1 1.5 -- --

64. Hydrogen Sulphide 10 14 15 21

65. Gasoline 300 900 500 1500

66. Iodine -C 0.1 1 -- --

67. Iron Oxide Fume (Fe O )(as Fe) - 5 -- --

2 3

68. Isoamyl acetate 100 525 -- --

69. Isoamyl alcohol 100 360 125 450

70. Isobutyl alcohol 50 150 -- --

71. Lead, inorg, dusts and fumes (as Pb) -- 0.15 -- --

72. Lindane-skin -- 0.5 -- --

73. Malathion-skin -- 10 -- --

74. Manganese dust and compounds(as Mn) -- 5 -- --

75. Manganese Fume (as Mn) -- 1 -- 3

76. 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 -- --

77. Methyl alcohol (methanol)-skin 200 260 250 310

78. Methyl cellosolve-skin (2 methoxy 5 16 -- --

ethanol)-scin

79. MMeetthhyyll IIssoobbuuttyyll KKeettoonnee 50 205 75 300

80. Methyl Isocyanate 0.02 0.05 -- --

81. Naphthalene 10 50 15 75

82. NNiicckkeell ccaarrbboonnyyll ((aass NNii)) 0.05 0.35 -- --

83. Nitric acid 2 5 4 10

84. Nitric oxide 25 30 -- --

85. Nitrobenzene-skin 1 5 -- --

86. Nitrogen dioxide 3 6 5 10

87. Oil mist, minerals -- 5 -- 10

88. Ozone 0.1 0.2 0.3 0.6

89. Parathion-skin -- 0.1 -- --

90. Phenol-skin 5 19 -- --

91. Phorate (Thimet)-sskkiinn -- 0.05 -- 0.2

92. PPhhoossggeennee ((CCaarrbboonnyyll CChhlloorriiddee 0.1 0.4 -- --

93. Phosphine 0.3 0.4 1 1

94. PPhhoosspphhoorriicc aacciidd ((yyeellllooww)) -- 1 -- --

95. PPhhoosspphhoorruuss ((yyeellllooww)) -- 0.1 -- --

96. PPhhoosspphhoorruuss ppeennttaacchhlloorriiddee 0.1 1 -- --

97. PPhhoosspphhoorruuss ttrriicchhlloorriiddee 0.2 1.5 0.5 3

98. Picric acid-skin -- 0.1 -- 0.3

99. Pyridine 5 15 -- --

100. SSiillaannee ((ssiilliiccoonn tteettrraahhyyddrriiddee)) 5 7 -- --

101. Sodium hydroxide-CC -- 2 -- --

102. SSttyyrreennee,, mmoonnoommeerr ((PPhheennyylleetthhyylleennee)) 50 215 100 425

103. Sulphur dioxide 2 5 5 10

104. SSuullpphhuurr hheexxaafflluuoorriiddee 1000 6000 -- --

105. Sulphuric acid -- 1 -- --

106. Toluene (Toluol) 100 375 150 560

107. O-Tuluiodine-sskkiinn ((SS..CC..)) 2 9 -- --

108. Tributyl phosphate 0.2 2.5 -- --

109. Trichloroethylene 50 270 200 1080

110. UUrraanniiuumm,, nnaattuurraall ((aass UU)) -- 0.2 -- --

111. VViinnyyll cchhlloorriiddee((HH..CC..)) 5 10 -- --

112. Welding fumes -- 5 -- --

113. Xylene (o-, m, p-iissoommeerrss)) 100 435 150 655

114. Zinc oxide

(i)Fume -- 5 -- 10

((iiii)) DDuusstt ((TToottaall dduusstt)) -- 10 -- --

115. ZZiirroonniiuumm ccoommppoouunnddss ((aass ZZrr)) -- 5 -- 10

ppppmm:: PPaarrttss ooff vvaappoouurr oorr ggaass ppeerr mmiilllliioonn ppaarrttss ooff ccoonnttaammiinnaatteedd aaiirr bbyy vvoolluummee aatt 2255°° CC aanndd 776600 mmmm ooff HHgg..

mg/m3 :: mmiilllliiggrraamm ooff ssuubbssttaannccee ppeerr ccuubbiicc mmeettrree ooff aaiirr

***,,,:::NNNooottteee mmmooorrreee ttthhhaaannn 444 tttiiimmmeeesss aaa dddaaayyy wwwiiittthhh aaattt llleeeaaasssttt 666000 mmmiiinnn... iiinnnttteeerrrvvvaaalll bbbeeetttwwweeeeeennn sssuuucccccceeessssssiiivvveee eeexxxpppooosssuuurrreeesss...

**,: mg/m3 xx ppppmm

G,: denotes Ceiling Limit

Skin,: denoteeesss pppooottteeennntttiiiaaalll cccooonnntttrrriiibbbuuutttiiiooonnn tttooo ttthhheee ooovvveeerrraaallllll eeexxxpppooosssuuurrreee bbbyyy ttthhheee cccuuutttaaannneeeooouuusss rrrooouuuttteee iiinnncccllluuudddiiinnnggg mmmuuucccooouuusss

membranes and eye.

SS..CC..,,::ddeennootteess ssuussppeecctteedd HHuummaann CCaarrcciinnooggeenn

HH..CC..ddeennootteess CCoonnffiirrmmeedd HHuummaann CCaarrcciinnooggeenn

Permisible time-wweeiigghhtteedd aavveerraaggee ccoonncceennttrraattiioonn

SSuubbssttaannccee

((TTWWAA))((88 hhrs)

(i) Silica,SiO

2

(a) Crystaline

(i) Quartz

(1) In terms of dust count 1100660000 // ((%% QQuuaarrttzz ++ 1100)) mmppppccmm

(2) In terms of respirable dust 1100 // ((%% rreessppiirraabbllee qquuaarrttzz ++ 22)) mmgg//mm3

(3) In terms of total dust 3300 // ((%% rreessppiirraabbllee qquuaarrttzz ++ 33)) mmgg//mm3

(ii) Cristabalite Half the limits given against quartz.

(iii) Tridymine Half the limits given against quartz.

(iv) Silica fused Same limit as for quartz.

(v)Tripoli: Same limit as in formula in item 2 given against quartz.

(b) Amorphous silicates: 10mg/m3 Total dust.

[Asbestos (H.C.):

(a) Amosite..................................0.1 fibre/cc***

(b) Chrystolite...... .0.1 fibre/ cc***

(c) Crocidolite...... .0.1 fibre/ cc***

Portland Cement: 10 mg/mº, total dust containing less than 1% quartz

Coal Dust: 2 mg/mº, respirable dust fraction containing less than 5% quartz.

mppcm = Million particles per cubic metre of air, based on impinge samples counted by light-field

techniques.

***(i) For fibres greater than 5 µm in length and less than 5 µm in breadth with length to breadth ration

equal to or greater than 3:1.

(ii) As determined by the membrane filter method at 400-450 × magnification (4 µm bjective) phase

contrast illumination.

Respirable Dust :

Fraction passing a size-selector with the following characteristics:

__________________________________________________________________________________

Aerodynamic Diameter (µ m) (Unit density sphere) % passing selector

__________________________________________________________________________________

2 90

2.5 75

3.5 50

5.0 25

10 01

__________________________________________________________________________________

Permissible activity concentration levels for some of the radionuclides that are commonly encountered in

metal recycling industries as given below :

Radionuclide Radionuclide concentration

(Bq/g*)

Co-60 0.1

Cs-137 0.1

Am-241 0.1

Ir-192 1.0”

Footnote :

1. Bq/g stands for Becquerel per gram. Becquerel means one transformation of a radionuclide per

second : and is the SI unit of radioactivity.

2. Measurement shall comprise external radiation levels on the metal scrap, semi-finished and

finished products as well as the background levels at the place of measurement and records of

the same shall be maintained. If the radiation level on the material exceeds the background

radiation level by 20 µ/hr (Micro Rad per hour).

3. The Atomic Energy Regulatory Board (AERB) Shall be promptly intimated.