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
|
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