ATEX DIRECTIVES

The ATEX Directive (94/9/EC) regulates that manufacturers are forced to supply ONLY properly certified electrical equipment to be used in potentially explosive areas.
From the workers side there is another ATEX Directive (99/92/EC) that regulates the requirements for improving the safety and health protection of workers potentially at risk from explosive atmospheres.
Both Directives are mandatory.

These Directives state that each area needs to be classified according to the potential hazardous risk so that only appropriate certified equipment can be used there.
With the old CENELEC (previous Directive), different areas were divided into three classifications: Zone 2, Zone 1, and Zone 0 depending on the level of risk.
With the ATEX Directive, every Zone is associated to a Category, and every electrical equipment is classified according to these categories, certifying in which areas it can be safely used.