Home > ATEX Categories 1, 2 and 3: what do they mean for fans?

ATEX Categories 1, 2 and 3: what do they mean for fans?

Once the ATEX zone of a location has been established, the next question is: which equipment category is required? The category translates the zone into concrete construction requirements for the fan. This article explains how categories work, what equipment groups are, and what it means in practice for your fan specification.

From zone to category: the direct link

The ATEX directive establishes a direct relationship between zone and the minimum required equipment category:

Zone 0 / Zone 20 → minimum category 1 (G or D)
Zone 1 / Zone 21 → minimum category 2 (G or D)
Zone 2 / Zone 22 → minimum category 3 (G or D)

The designation G stands for Gas (zones 0, 1 and 2), D stands for Dust (zones 20, 21 and 22). A fan suitable for zone 1 carries the marking Category 2G, or the more modern designation EPL Gb.

Read our knowledge article on ATEX zones for more information.

Equipment groups: I, II and III

In addition to categories, ATEX also defines equipment groups, which indicate the type of environment the equipment is intended for:

Group I: Mining (underground, firedamp/mine gas)
Group II: Other industrial installations involving gas, vapour or mist (most common)
Group III: Environments with combustible dust (other than mining dust)

Group II: by far the most relevant for manufacturing, chemicals, food processing and tunnels — is further subdivided into IIA, IIB and IIC based on the ignitability of the gas. IIC covers the most easily ignitable gases, including hydrogen and acetylene. A fan certified for IIC is always suitable for IIA and IIB environments as well.

What does this mean in practice for a fan?

Consider a zone 2 environment containing propane (group IIA). In this case, you need a fan carrying at minimum the marking category 3G, group II. In practice, you would select a fan marked: II 3G or ⟨Ex⟩ II 3G c IIA T3. All components, from the impeller to the motor and the coating, must meet the corresponding construction requirements as set out in EN 14986.

Note: always select the category that corresponds to the zone, unless there are specific reasons, such as more severe consequences in the event of ignition, to opt for a higher category.

EPL: Equipment Protection Level

Alongside category designations, EPL markings are increasingly used: Ga, Gb, Gc (for gas) and Da, Db, Dc (for dust). EPL is the international harmonisation with IECEx and indicates the same level of protection, but in an internationally recognised notation. Ga represents the highest level of protection (equivalent to category 1G), Gb corresponds to category 2G, and Gc to category 3G.