B8.5.1 COMAH continued…
Application of COMAH
COMAH applies to sites that keep, transport or use quantities of dangerous substances listed in the regulations, over certain threshold limits. This is mainly the chemical industry, but does include other types of industry that use, transport or store dangerous substances.
The thresholds for the dangerous substances are set at 2 limits. Sites that are affected by the higher quantities are referred to as “Top Tier” sites, whilst those under the lower quantities are referred to as “Lower Tier” sites. The requirements under the regulations differ for each Tier.
| Schedule 1 PART 2 Named Substances | ||
| Dangerous substances | Low Tier | Top Tier |
| 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 |
Source: The Control of Major Accident Hazards Regulations 1999 [SI. No 743]