26 Apr

The ATEX Directive: An Absolute Beginner’s Guide

What is the ATEX Directive all about and why does it matter?

ATEX Directive post image by Denis Starostin (via Shutterstock).

An ATEX Directive PLC and barriers panel board. Image by Denis Starostin (via Shutterstock).

If you have used electrical equipment in an explosive environment, you may have come across this hexagonal logo seen below. This is used to denote the equipment’s suitability for explosive environments as per the ATEX Directive.

ATEX Directive Logo

The ATEX Directive logo.

ATEX is based on two European Union directives. There is one for the manufacturer of, and another one for users of ATEX compliant equipment. For manufacturers, the ATEX 95 (94/9/EC) directive applies, focusing on equipment and protective systems intended for use in potentially explosive atmospheres. For equipment users, ATEX 137 (99/92/EC) applies. These set minimum safety standards for the welfare of workers at risk from explosive atmospheres.

Throughout EU Member States, the above ATEX Directives have been effective since July 2003. For manufacturers, the original ATEX Directive (94/9/EU) was superseded by 2014/32/EU on the 20 April 2016.

ATEX Zones

The ATEX Directive also has six zones. Three of them refer to dust related hazards, should any speck of dust trigger an ignition. These are as follows:

  • Zone 0: any place where the chances of explosion with dangerous substances – gas, vapour, or mist – are great, either continuously or for long periods;
  • Zone 1: any place where the chances of explosion with dangerous substances – gas, vapour, or mist – are sporadic, under normal conditions;
  • Zone 2: any place where the chances of explosion with dangerous substances – gas, vapour, or mist – are unlikely to happen under normal conditions (though any reaction may be for short periods);
  • Zone 20: any place where a cloud of combustible dust and an explosive atmosphere is present all the time, at frequent intervals, or for long periods;
  • Zone 21: any place where a cloud of combustible dust and an explosive atmosphere is present under normal conditions;
  • Zone 22: any place where a cloud of combustible dust and an explosive atmosphere is unlikely to happen under normal conditions (though any reaction may be for short periods).

As to where ATEX’s name is derived from, it is based on the French title of the EU Directive: Appareils destinés à être utilisés en ATmosphères EXplosibles.

Total Control and Distribution, 26 April 2017.

About the Author

Leave a Reply