ATEX Zones vs IECEx Classes

ATEX Zones vs IECEx Classes, both ATEX and IECEx  describe what equipment and work space is allowed in an environment with an explosive atmosphere. Both regulations are much alike in their intention and implementation.

For most countries however, they are not interchangeable and equipment in an explosive atmosphere will have to be either ATEX or IECEx compliant.

This article will explains which countries require ATEX or IECEx. The similarities between corresponding ATEX zones and IECEx divisions are represented in a table at the end.

In which countries does ATEX apply?

ATEX derives its name from the French title of the 94/9/EC directive: Appareils destinés à être utilisés en ATmosphères EXplosives. Therefore it is no surprise that ATEX is used for explosion safety regulations in most European countries.


An ATEX marked explosive atmosphere

In which countries does IECEx apply?

Where ATEX mainly applies in Europe, IECEx is globally accepted. IECEx is the only certificate that applies in Canada, Brazil, Russia and the United States. In Europe, IECEx applies, but ATEX is used more often, also depending on the country.

IECEx and ATEX both apply in most parts of Asia, Africa and the Middle-East. In these parts of the world, IECEx is more commonly used than ATEX.

ATEX Zones vs IECEx Classes & Divisions

When using ATEX regulations, hazardous areas are split into zones. Zones 20, 21 and 22 are used when classifying dust explosive atmospheres, zones 0, 1 and 2 are used for gas explosive atmospheres.

Zones 0 and 20 are exposed to the highest risk of an explosion and therefore have the strictest regulations for operations and equipment. For all about ATEX zones and explosion risks, please refer to our infographic; ATEX Zones and Equipment Categories

IECEx Classes & Divisions

In IECEx regulations, classes are used to describe wheter an explosive atmosphere is caused by dust or by gas. Gas explosive atmospheres belong to class I. To describe a dust explosive atmosphere, class II is used.

Where ATEX uses 3 levels to describe the intensity of an explosion risk, IECEx only uses two; namely division I and division II. ATEX Zones 2 and 22 correspond to division II. Zones 20, 21, 0 and 1 correspond to IECEx division I.

ATEX zones vs IECEx Classes & Divisions Table:

Explosive Atmosphere TypeExplosion RiskATEX ZoneIECEx ClassIECEx Division
GasHighestZone 0Class IDivision I
GasHighZone 1Class IDivision I
GasModerateZone 2Class IDivision II
DustHighestZone 20Class IIDivision I
DustHighZone 21Class IIDivision I
DustModerateZone 22Class IIDivision II