ATEX Zones and Equipment Categories
ATEX zones and equipment categories describe how explosive atmospheres are classified and which equipment may be used within them. Zones rate how often and for how long a flammable gas, vapour or dust atmosphere is present, while equipment categories define the level of protection a device provides for use in those zones.
Key Takeaways
ATEX zones classify how frequently and for how long an explosive atmosphere is present.
Gas atmospheres use Zones 0, 1 and 2, while dust atmospheres use Zones 20, 21 and 22.
Equipment categories 1, 2 and 3 define increasing tolerance of zone severity, suffixed G for gas and D for dust.
Selecting compliant equipment means matching the equipment category to the zone classification of the area.
An area is assigned a zone based on how often a flammable atmosphere occurs. Zone 0 has a continuous or long term presence of flammable gas, Zone 1 a likely presence in normal operation and Zone 2 an unlikely or short lived presence. Dust atmospheres follow the same pattern as Zones 20, 21 and 22.
Equipment is assigned a category that reflects how much protection it provides. Category 1 equipment is suitable for the most severe zones, Category 2 for the next level and Category 3 for the least severe, with a G or D suffix indicating gas or dust use.
A device must carry a category appropriate to the zone in which it will be used. For example, a Zone 2 area requires at least Category 3G equipment, while more hazardous zones demand higher category devices.
Rugged tablets and phones for oil and gas, chemical and mining sites state their ATEX zone and category so that engineers can confirm the device is approved for the specific hazardous area in which it will be deployed.
Frequently Asked Questions
A zone describes how often an explosive atmosphere is present in an area, while an equipment category describes the level of protection a device provides for use in that area.
G indicates equipment for explosive gas atmospheres and D indicates equipment for combustible dust atmospheres.
A Zone 2 gas area requires at least Category 3G equipment, although higher category devices may also be used.
They follow the same three level structure, with gas using Zones 0, 1 and 2 and dust using Zones 20, 21 and 22.
From Theory to Application
Now that you've mastered the specs, get the gear that survives them.
