ATEX Directive

Any control equipment used to ensure the safe operation of equipment in a hazardous area falls within the scope of the ATEX Directive (from the French – Atmospheres Explosive). The ATEX Directive combines two European Directives associated with equipment used in and people who work in potentially explosive atmospheres. It not only considers potentially explosive concentrations of gas, vapor or mist in the air, but also concentrations of dust. It accounts for both electrical and mechanical sources of ignition. It also concerns the minimum requirements for improving safety and health protection of workers at risk from explosive atmospheres. An Explosive Atmosphere is the mixture of flammable substances in the form of gases, vapors, mists or dusts with air.

Gas, Mists or Vapors

Zone 0 — An atmosphere where a mixture of air and flammable substances in the form of gas, vapor or mist is present frequently, continuously or for long periods.

Zone 1 — An atmosphere where a mixture of air and flammable substances in the form of gas, vapor or mist is likely to occur in normal operation occasionally.

Zone 2 — An atmosphere where a mixture of air and flammable substances in the form of gas, vapor or mist is not likely to occur in normal operation but, if it does occur, will persist for only a short period.