Which ATEX zones are differentiated and what do they mean?

ATEX distinguishes different hazardous zones based on the presence of potentially explosive gas or dust atmospheres.

The classification depends on how often and how long an explosive atmosphere may occur in the work environment. These zones determine which equipment and safety systems may be used.

Gas explosion zones

(flammable gas, vapour, or mist mixed with air)

• Zone 0 — Explosive atmosphere is present continuously or for long periods
• Zone 1 — Explosive atmosphere may occur occasionally during normal operation
• Zone 2 — Explosive atmosphere occurs rarely and only for a short time

Dust explosion zones

(combustible dust clouds)

• Zone 20 — Explosive dust atmosphere is continuously present or present for long periods
• Zone 21 — Explosive dust atmosphere may occur occasionally during normal operation
• Zone 22 — Explosive dust atmosphere occurs rarely and only briefly

The lower the zone number, the higher the explosion risk and the stricter the safety requirements for the work environment, equipment, and protection systems.

For more information about ATEX regulations and certified equipment, please visit our ATEX information page.