Area Classification
| Guideline figures | Flammable atmosphere present | Standard | |||
| Continuously > 1000hrs/annum | Intermittently >10 < 1000hrs/annum | Abnormally < 10hrs/annum | |||
| IEC / Cenelec / Europe | Gas | Zone 0 | Zone 1 | Zone 2 | IEC 60079-10 |
| Dust | Zone 20 | Zone 21 | Zone 22 | IEC 61241-3 | |
| North America | NEC 505 Gas | Zone 0 | Zone 1 | Zone 2 | Listed in NEC 505-5 |
| NEC 500 Gas & dust | Division 1 | Division 2 | Listed in NEC 500-3(c) | ||
