| Nr | Description of possible ignition sources |
| 1 | Hot surfaces |
| 2 | Flames and hot gasses (inc. Glowing particles) |
| 3 | Mechanically caused sparks |
| 4 | Electrical equipment |
| 5 | Stray currents and cathodic protection |
| 6 | Static electricity |
| 7 | Lightning |
| 8 | Radio frequent interference 104Hz < f < 1011Hz |
| 9 | Electro magnetic waves from 3x 1011Hz till 1015HZ |
| 10 | Ionizing radiation |
| 11 | Ultrasonic sound |
| 12 | Adiabatic compression and shock waves |
| 13 | Exothermic reactions, including self-ignition of dust |