# The Control of Substances Hazardous to Health (Amendment) Regulations 1991, Schedule 1: SCHEDULE TO BE SUBSTITUTED AS SCHEDULE 1 TO THE PRINCIPAL REGULATIONS


SCHEDULE 1
LIST OF SUBSTANCES ASSIGNED MAXIMUM EXPOSURE LIMITS
Regulations 2(1), 7(4) and 12(2)
The maximum exposure limits of the dusts included in the list below refer to the toinhalable dust fraction, unless otherwise stated.
Substance
Formula
Reference periods
Long-term maximum exposure limit (8-hour TWA reference period)
Short-term maximum exposure limit (10-minute reference period)
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 ml1, 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 and compounds except arsine (as As)
As
—
0.1
—
—
Benzene
C6H6
75
15
—
—
Buta-1,3-diene
CH2=CHCH=CH2
10
22
—
—
2-Butoxyethanol
C4H9OCH2CH2OH
25
120
—
—
Cadmium and cadmium compounds, except cadmium oxide fume and cadmium sulphide pigments (as Cd)
Cd
—
0.05
—
—
Cadmium oxide fume (as Cd)
CdO
—
0.05
—
0.05
Cadmium sulphide pigments (respirable dust as Cd)
CdS
—
0.04
—
—
Carbon disulphide
CS2
10
30
—
—
Chromium (VI) compounds (as Cr)
Cr
—
0.05
—
—
1,2–Dibromoethane (Ethylene dibromide)
BrCH2CH2Br
0.5
4
—
—
Dichloromethane
CH2Cl2
100
350
—
—
2,2'–Dichloro–4,4'–methylene dianiline (MbOCA)
CH2(C6H3ClNH2)2
—
0.005
—
—
2-Ethoxyethanol
C2H5OCH2CH2OH
10
37
—
—
2-Ethoxyethyl acetate
C2H5OCH2CH2OOCCH3
10
54
—
—
Ethylene oxide
CH2CH2O
5
10
—
—
Formaldehyde
HCHO
2
2.5
2
2.5
Grain dust
—
10
—
—
Hydrogen cyanide
HCN
—
—
10
10
Isocyanate, all (as-NCO)
—
0.02
—
0.07
Man-made mineral fibre
—
5
—
—
2-Methoxyethanol
CH3OCH2CH2OH
5
16
—
—
2-Methoxyethyl acetate
CH3COOCH2CH2OCH3
5
24
—
—
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
—
—
Rubber process dust
—
8
—
—
Rubber fume
—
0.6
—
—
Silica, respirable crystalline
SiO2
—
0.4
—
—
Styrene
C6H5CH=CH2
100
420
250
1,050
1,1,1-Trichlorotehane
CH3CCl3
350
1,900
450
2,450
Trichloroethylene
CCl2=CHCl
100
535
150
802
Vinyl chloride
CH2=CHCl
7
—
—
—
Vinylidene chloride
CH2=CCl2
10
40
—
—
Wood dust (hard wood)
—
5
—
—

---
Source: https://www.legislation.gov.uk/uksi/1991/2431/schedule/1 (the official version)
Page: https://openlegislation.uk/control-of-substances-hazardous-to-health-amendment-regulations-1991/schedule-1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.