THE SECOND SCHEDULE

(See Section 41-F)

Permissible Levels of Certain Chemical substances in work environment

 

Sl.

No.

Substances

Permissible Limits of Exposure

Time-Weighted Average- Concentration (TWA)

(8 hrs.)

Short-term exposure Limit STEL

(15 min)

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

1,780

1,000

2,375

4

Acrolein

0.1

0.25

0.3

0.8

5.

Acrylonitrile-Skin(S.C)

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 & soluble compounds (as As)

--

0.2

--

--

2[12

Benzene (H.C.)

0.5

1.5

2.5

7.5]

13

Beryllium & compounds (as Be (S.C.)

--

0.002

--

--

14

Boron  trifluoride-C

1

3

--

--

15

Bromine

0.1

0.7

0.3

2

16

Butane

800

1,900

--

--

17

2-Butanone (Metyl ethyl Ketone-MEK)

200

590

300

885

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

Chlordane –Skin

--

0.5

--

2

30

Chlorine

1

3

3

9

 

1.  Ins. by Act 20 of 1987, S.45 (w.e.f. 1.12.1987)

2. Subs. by S.O.342(E) dt.19.4.2001(w.e.f.) 19.4.2001, Gaz. of India Ext.247, dt. 19.4.2001. Pt.II, Sec.3(ii).

 

 

1

2

3

4

5

6

31

Chlorobenzene  (Monochlorobenzene)

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) (Water soluble)

--

0.05

--

--

35

Chrombus salts (as Cr)

--

0.5

--

--

36

Copper Fume

--

0.2

--

--

37

Cotton Dust, raw

--

0.2 *1

--

--

38

Cresol, all isomers-Skin

5

22

--

--

39

Cyanide (as CN)-Skin

--

5

--

--

40

Cyanogen

10

20

--

--

41

DDT  (Dichlorodiphenyl trichlorothane)

--

1

--

--

42

Demeton-Skin

0.01

0.1

--

--

43

Diazinon-Skin

--

0.1

--

--

44

Dibutyl phthalate

--

5

--

--

45

Dichlorvos (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

1,400

--

--

53

Enthyl alcohol

1,000

1,900

--

--

54

Ethylamine

10

18

--

--

55

Fluoride (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

1,500

60

Hydrazine-skin (S.C.)

0.1

0.1

--

--

61

Hydrogen chloride-C

5

7

--

--

62

Hydrogen cyanide-Skin-C

10

10

--

--

63

Hydrogen fluoride(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 (Fe2 O3 (as Fe)

--

5

--

--

68

Isoamyl acetate

100

525

--

--

1   *Lint-free dust as measured by the vertical elutricator cotton dust sampler.

 

1

2

3

4

5

6

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)-C

--

5

--

--

75

Manganese fume (as Mn)

--

1

--

0.03

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 (2-Methoxyethanol)-Skin

5

16

--

--

79

Methyl isobutyl ketone

50

205

75

300

80

Methyl isocyanate-Skin

0.02

0.05

--

--

81

Naphthalene

10

50

15

75

82

Nickel carbonyl (as Ni)

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 mineral

--

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)-Skin--

--

0.05

--

0.2

92

Phosgene (Carbonyl chloride)

0.1

0.4

--

--

93

Phosphine

0.3

0.4

1

1

94

Phosphoric acid (yellow)

--

1

--

3

95

Phosphorus (yellow)

--

0.1

--

--

96

Phosphorus pentachloride

0.1

1

--

--

97

Phosphorus trichloride

0.2

1.5

0.5

3

98

Picric acid-Skin

--

0.1

--

0.3

99

Pyridine

5

15

--

--

100

Silane (Silicon tetrahydride

5

7

--

--

101

Sodium hydroxide C

--

2

--

--

102

Styrene, monomer (Phenylethylene)

50

215

100

425

103

Sulphur dioxide

2

5

5

10

104

Sulphur hexafluoride

1,000

6,000

--

--

105

Sulphuric Acid

--

1

--

--

106

Tetraethyl lead (as Pb)-Skin

--

0.1

--

--

107

Toluene (Toluol)

100

375

150

560

108

O-Tuluidine-Skin (S.C)

2

9

--

--

109

Tributyl Phosphate

0.2

2.5

--

--

110

Trichloroethylene

50

270

200

1,080

111

Uranium, natural (as U)

--

0.2

--

0.6

112

Vinyl chloride (H.C.)

5

10

--

--

113

Welding fumes

--

5

--

--

114

Xylene (o-,m-, p-isomers 

100

435

150

655

115

Zinc oxide

 

 

 

 

(i) Fume

--

5.0

--

10

(ii)Dust (Total dust)

--

10.00

--

--

116

Zirconium compounds (as Zr)

--

5

--

10

 

 

ppm :

Parts of vapour or gas per million parts of contaminated air by volume at 25OC and 760 toor (mm of mercury)

mg/m3     

milligram of substances per cubic metre of air.

*:

,.

Not more than 4 times a day with at least 60 min.

internal between  successive exposures

**:

                                              Molecular weight

                    mg/m3     ----------------------------------x 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.

 

 

----------------------------------------------------------------------------------------------------------

Substance                                      Permissible time-weighted average concentration

                                                                                    (TWA) (8 hours)

----------------------------------------------------------------------------------------------------------

 

Silica, Si O2

            (a) Crystalline

                 (i)  Quartz

 

                                                                                    10600

(1)      In terms of dust count  ------------------------------------- mppcm

                                                     % Quartz + 10

 

                                                              10

(2)      In terms of respirable dust  --------------------------------- mg/m3

                                                    % respirable Quartz + 2

 

                                                               30

(3)  In terms of total dust   -------------------------------------- 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)    Tripoli          : Same limit as in formula in item (2) given

                                                   against quartz

                                                    

 

            (b) Amorphous Silicates : 10 mg/m3, Total Dust

                    [Asbestos (H.C.

(a)    Amosite  ………………………………0.5 fibre/cc***

(b)    Chrystolite …………………………….1.0 fibre/cc***

(c)    Crocidolite ……………………………..0.2 fibre/cc***]

 

Portland cement  :   10 mg/m3, Total dust containing less than 1% quartz.

 

Coal Dust           :  2mg/m3, respirable dust fraction containing less than

                              5% quartz.

 

------------------------------------------------------------------------------------------------------

 

mppcm : Million particles per cubic metre of air, based on impinger samples counted by light field techniques.

 

*** (i)  For fibres greater than 5 um in length and less than 5 um in breadth with length to  breadth ratio equal to or greater  than 3:1.

 

       (ii) As determined by the membrane filter method at 400-450 x magnification (4mm 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

 

2. Subs. by S.O.342(E) dt.19.4.2001(w.e.f.) 19.4.2001, Gaz. of India Ext.247, dt. 19.4.2001. Pt.II, Sec.3(ii).

 

 

Date  : 4th June, 2007