# The Control of Substances Hazardous to Health Regulations 1994, Schedule 1: LIST OF SUBSTANCES ASSIGNED MAXIMUM EXPOSURE LIMITS


The maximum exposure limits of the dusts included in the list below refer to the total inhalable dust fraction, unless otherwise stated.
Reference periods
Long-term maximum exposure limit (8-hour TWA reference period)
Short-term maximum exposure limit (15-minute reference period)
Substance
Formula
ppm
mg m−3
ppm
mg m−3
° In addition to the maximum exposure limit specified above man-made mineral fibre is also subject to a maximum exposure limit of 2 fibres ml−1, 8-hour TWA, when measured or calculated by a method approved by the Health and Safety Commission.
* Limit relates to cyclohexane soluble material.
# In addition to the maximum exposure limit specified above vinyl chloride is also subject to an overriding annual exposure limit of 3 ppm.
Acrylamide
CH2=CHCONH2
—
0.3
—
—
Acrylonitrile
CH2=CHCN
2
4
—
—
Arsenic & compounds except arsine (as As)
As
—
0.1
—
—
Benzene
C6H6
5
16
—
—
Beryllium and beryllium compounds (as Be)
Be
—
0.002
Bis (chloromethyl) ether
C1CH2OCH2C1
0.001
0.005
—
—
Buta-1, 3-diene
CH2=CHCH=CH2
10
22
—
—
2-Butoxyethanol
C4H9OCH2CH2OH
25
120
—
—
Cadmium & cadmium compounds, except cadmium oxide fume, cadmium sulphide and cadmium sulphide pigments (as Cd)
Cd
—
0.025
—
—
Cadmium oxide fume (as Cd)
CdO
—
0.025
—
0.05
Cadmium sulphide and cadmium sulphide pigments (respirable dust as Cd)
CdS
—
0.04
—
—
Carbon disulphide
CS2
10
30
—
—
Chromium (VI) compounds (as Cr)
Cr
—
0.05
—
—
Cobalt and cobalt compounds (as Co)
Co
—
0.1
—
—
1,2-Dibromoethane (Ethylene dibromide)
BrCH2CH2Br
0.5
4
—
—
1,2-Dichloroethane (Ethylene dichloride)
C1CH2CH2C1
5
20
—
—
Dichloromethane
CH2C12
100
350
300
1050
2,2'-Dichloro-4,4'-methylene dianiline (mboca)
CH2(C6H3C1NH2)2
—
0.005
—
—
1-Chloro-2,3-epoxypropane (Epichlorohydrin)
0.5
2
1.5
6
2-Ethoxyethanol
C2H5OCH2CH2OH
10
37
—
—
2-Ethoxyethyl acetate
C2H5OCH2CH2OOCCH3
10
54
—
—
Ethylene oxide
5
10
—
—
Formaldehyde
HCHO
2
2.5
2
2.5
Grain dust
—
10
—
—
Hydrogen cyanide
HCN
—
—
10
10
Isocyanates, all (as-NCO)
—
0.02
—
0.07
Man-made mineral fibre
—
5
—
—
2-Methoxyethanol
CH3OCH2CH2OH
5
16
—
—
2-Methoxyethyl acetate
CH3COOCH2CH2OCH3
5
24
—
—
4, 4'-Methylenedianiline
CH2(C6H4NH2)2
0.01
0.08
—
—
Nickel and its inorganic compounds (except nickel carbonyl):
Ni
water-soluble nickel compounds (as Ni)
—
0.1
—
—
nickel and water-insoluble nickel compounds (as Ni)
—
0.5
—
—
2-Nitropropane
CH3CH(NO2)CH3
5
18
—
—
Rubber process dust
—
6
—
—
Rubber fume
—
0.6
—
—
Silica, respirable crystalline
SiO2
—
0.4
—
—
Styrene
C6H5CH=CH2
100
420
250
1050
1, 1, 1-Trichloroethane
CH3CC13
350
1900
450
2450
Trichloroethylene
CC12=CHC1
100
535
150
802
Vinyl chloridea
CH2=CHC1
7
—
—
—
Vinylidene chloride
CH2=CC12
10
40
—
—
Wood dust (hard wood)
—
5
—
—

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Source: https://www.legislation.gov.uk/uksi/1994/3246/schedule/1 (the official version)
Page: https://openlegislation.uk/control-of-substances-hazardous-to-health-regulations-1994/schedule-1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.