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HAZARDOUS AREAS · ZONES

What Are ATEX Zones?

ATEX zones classify a hazardous area by how often an explosive atmosphere is present. For gases and vapours, Zone 0 means continuously or for long periods, Zone 1 means likely in normal operation, and Zone 2 means unlikely and only briefly. Dust areas follow the same pattern as Zones 20, 21 and 22.

01

The Short Answer

The zone decides what equipment is allowed. Most computers and HMIs in hazardous areas are installed in Zone 2, near process equipment where a leak is possible but not expected. Zone 1 and Zone 0 call for more protective designs, such as intrinsically safe or flameproof equipment.

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    Zone 0 and 20 Only category 1 equipment, typically intrinsically safe sensors and instruments.
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    Zone 1 and 21 Category 2 equipment, such as flameproof or purged enclosures.
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    Zone 2 and 22 Category 3 equipment, where most hazardous area panel PCs are used.
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    Outside the zones Standard industrial equipment, often in a control room.
02

Why It Matters

In North America, Zone 2 corresponds broadly to Division 2; our Class 1 Division 2 FAQ compares the two, and our ATEX FAQ explains the marking. Our hazardous area panel PCs cover the range.