ATEX Explained

The ATEX Explosion Protection regulations

When mechanical or electrical equipment is to be situated in a hazardous area it must be ATEX certified as required by the EU directive 94/9/EC. This directive is more commonly known as the ATEX directive.

Hazardous areas are those where a potentially explosive mix of air and flammable gasses or air and dust or air, dust and gasses may occur.

Outside of the European Union similar regulations apply under the IECEX certification system. In North America products must be listed by UL as suitable for use in hazardous atmospheres. Please note that while the ATEX and IECEX certification system are similar, the North American approach is different; see area classification below.

Scope of ATEX

ATEX certification of products for use in potentially hazardous atmospheres is compulsory.

Classification of ATEX equipment

The ATEX directive classifies equipment into groups and categories which are defined by the marking on the equipment – see “Product marking” below.

Classification of an ATEX area

Hazardous areas are divided into Zones (European and IECEX method) or Classes and Divisions (North American method) according to the likelihood of a potentially explosive atmosphere being present.

The ATEX directive requires the product to be marked with the CE mark, the ‘EX’ mark and the equipment coding as per table below.

* There are 8 methods of protection, for simplicity we have listed the 3 most commonly used.

ATEX Product marking example

An ATEX approved electrical product is marked with the following code:

From the breakdown of the code below it can be seen that the product is flameproof, suitable for use in zone 1 surface applications where gas group B gases may be present and the surface temperature of the product under fault conditions will not exceed 135 ºC.

UK ATEX Making

In the UK from the 1^st January 2023 the UK CA mark along with the registration of a UK based notifying body must also be incorporated onto ATEX product labelling