# The Control of Major Accident Hazards Regulations 1999, Part 2: Named Substances


Where a substance or group of substances listed in this Part also falls within a category of Part 3, the qualifying quantities set out in this Part must be used.
Column 1
Column 2
Column 3
Dangerous substances
Quantity in tonnes
Ammonium nitrate (as described in Note 1 of this Part)
350
2,500
Ammonium nitrate (as described in Note 2 of this Part)
1,250
5,000
Arsenic pentoxide, arsenic (V) acid and/or salts
1
2
Arsenic trioxide, arsenious (III) acid and/or salts
0.1
0.1
Bromine
20
100
Chlorine
10
25
Nickel compounds in inhalable powder form (nickel monoxide, nickel dioxide, nickel sulphide, trinickel disulphide, dinickel trioxide)
1
1
Ethyleneimine
10
20
Fluorine
10
20
Formaldehyde (concentration =>90%)
5
50
Hydrogen
5
50
Hydrogen chloride (liquefied gas)
25
250
Lead alkyls
5
50
Liquefied extremely flammable gases (including LPG) and natural gas (whether liquefied or not)
50
200
Acetylene
5
50
Ethylene oxide
5
50
Propylene oxide
5
50
Methanol
500
5,000
4, 4-Methylenebis (2-chloraniline) and/or salts, in powder form
0.01
0.01
Methylisocyanate
0.15
0.15
Oxygen
200
2,000
Toluene diisocyanate
10
100
Carbonyl dichloride (phosgene)
0.3
0.75
Arsenic trihydride (arsine)
0.2
1
Phosphorus trihydride (phosphine)
0.2
1
Sulphur dichloride
1
1
Sulphur trioxide
15
75
Polychlorodibenzofurans and polychlorodibenzodioxins (including TCDD), calculated in TCDD equivalent
0.001
0.001
The following CARCINOGENS:
4-Aminobiphenyl and/or its salts, Benzidine and/or salts, Bis(chloromethyl) ether, Chloromethyl methyl ether, Dimethylcarbamoyl chloride, Dimethylnitrosomine, Hexamethylphosphoric triamide, 2-Naphthylamine and/or salts, 1,3 Propanesultone and 4-nitrodiphenyl
0.001
0.001
Automotive petrol and other petroleum spirits
5,000
50,000

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Source: https://www.legislation.gov.uk/uksi/1999/743/schedule/1/part/2 (the official version)
Page: https://openlegislation.uk/control-of-major-accident-hazards-regulations-1999/schedule-1/part-2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.