Flammable Gases Vapours Dusts | Hazardous Area Guide to Explosive Atmospheres
Apparatus Groups and Common Flammable Gases, Vapours and Dust Types
| Gas Groups | Dust Groups | ||
| IIA | Propane | IIIA | Combustible |
| IIB | Ethylene | IIIB | Non-conductive |
| IIC | Hydrogen / Acetylene | IIIC | Conductive |
| Gas Vapour | Temperature class |
Apparatus group | Typical ignition temperature (°C) |
| Acetic acid | T1 | IIA | 427 |
| Acetone | T1 | IIA | 465 |
| Acetylene | T2 | IIC | 305 |
| Ammonia | T1 | IIA | 651 |
| Butane | T2 | IIA | 405 |
| Carbon Disulphine | T6 | IIC | 95 |
| Cyclohexane | T3 | IIA | 245 |
| Di-ethyl ether | T4 | IIB | 160 |
| Ethanol (ethyl alcohol) | T2 | IIA | 365 |
| Ethylene | T2 | IIB | 490 |
| Gasoline (petrol) | T3 | IIA | 280 |
| Hydrogen | T1 | IIC | 500 |
| Kerosene | T3 | IIA | 295 |
| Methane (natural gas) (non-mining) | T1 | IIA | 580 |
| Methanol (methyl alcohol) | T2 | IIA | 470 |
| Methyl ethyl ketone (MEK) | T2 | IIB | 505 |
| Propane | T1 | IIA | 470 |
| Propan-1-ol (n-propyl alcohol) | T2 | IIB | 371 |
| Propan-2-ol (iso-propyl alcohol) | T2 | IIA | 399 |
| Toluene | T1 | IIA | 535 |
| Xylene | T1 | IIA | 463 |
| Dusts | Apparatus group |
Typical ignition temperature cloud (°C) |
Typical ignition temperature layer (°C) |
| Aluminium | IIIC | 590 | >450 |
| Coal dust (lignite) | IIIB | 380 | 225 |
| Flour | IIIB | 490 | 340 |
| Grain dust | IIIB | 510 | 300 |
| Methyl cellulose | IIIB | 420 | 320 |
| Phenolic resin | IIIB | 530 | >450 |
| Polythene | IIIB | 420 | (melts) |
| PVC | IIIB | 700 | >450 |
| Soot | IIIB | 810 | 570 |
| Starch | IIIB | 460 | 435 |
| Sugar | IIIB | 490 | 460 |
