IEC 60079-10 — Zone Classification Standard Explained
IEC 60079-10-1 is the standard for the classification of gas explosive atmosphere zones. It provides the methodology for determining which areas of a plant should be classified as Zone 0, Zone 1, or Zone 2, and the extent of those zones.
Zone Definitions
| Zone | Definition |
|---|---|
| Zone 0 | Explosive atmosphere continuously present, or present for long periods |
| Zone 1 | Explosive atmosphere likely to occur in normal operation |
| Zone 2 | Explosive atmosphere unlikely in normal operation, but possible abnormally |
Factors Affecting Zone Extent
Zone classification takes into account: the release grade (continuous, primary, or secondary), the source of release (pump seals, flanges, sample points), ventilation (natural or forced), and the properties of the gas or vapour (density relative to air, LEL, UEL).
Zone Classification Documents
Plants are required to maintain zone classification drawings showing the extent of each hazardous zone. These drawings are the starting point for equipment selection — before installing or replacing any equipment, the inspector or installer must verify the zone classification for that location.
Reading about it is one thing. EX Academy puts you in the scenario — interactive inspection simulations, equipment selection decisions, and 1,185+ practice questions all referenced to IEC 60079. Try Simulation 01 and Scenario 01 completely free.
Try the Platform Free → More Articles