Chemicals and chemical groups associated with incidents in Wales, 1993–19952-150
| Chemicals | Number |
| Chemical, rubber, plastic, tyre and oil fires | 28 |
| Miscellaneous organics, including isocyanates | 17 |
| Harmful and toxic gases (NH3, Cl2, Br2, H2S, CS2, HCN, CO) | 17 |
| Flammable gases (methane, butane, propane, natural gas) | 15 |
| Agrochemicals | 14 |
| Solvents, solvent-based products, resins | 14 |
| General fires | 14 |
| Detergents, cleaning agents and damp proofing agents | 13 |
| Particulates and fume | 13 |
| Oil | 12 |
| Asbestos | 10 |
| Blue-green algae | 10 |
| Sulphuric acid | 9 |
| Phosphorus / phosphoric acid | 9 |
| Other petroleum hydrocarbons, including diesel and paraffin | 7 |
| Metals (Na, Hg, Cd, Cu, Pb, Fe) | 7 |
| Hydrochloric acid | 7 |
| Alkali (potassium and sodium hydroxide) | 7 |
| Petrol | 6 |
| Freon refrigerant | 6 |
| Other acids (sodium hypochlorite, chromic and nitric acids) | 6 |
| Red algae | 5 |
| Metal contaminated soils | 5 |
| Miscellaneous (munitions, landfill leachate, surface coating products) | 5 |
| Miscellaneous inorganics | 5 |
| Brown algae (phaeocystis) | 4 |
| Landfill gases | 4 |
| Radioactive substances | 3 |
↵2-150 Only those appearing in the database three or more times are listed.