ATEX - Protection against explosion risk

ATEX comes from the French word “atmosphère explosible”. This applies to all situations where people face an explosion risk. This may involve dust, fumes such as gasoline but for example also dust clouds from toner or flour. The ATEX legislation consists of: ATEX 114 directive and the ATEX 153 directive. These guidelines are intended to ensure that employers protect their staff against unsafe working situations. These two guidelines are included in the Commodities Act and the Working Conditions Act.

The ATEX 114 directive - formerly the ATEX 95 directive - determines which standards equipment and products must meet that are installed in potentially explosive atmospheres. These environments are called ATEX zones. This guideline also describes how manufacturers must indicate which requirements the equipment meets.

Explosion-proof equipment and products that comply with the ATEX 114 directive are provided with a hexagon symbol with 'ex' in it. As shown here.

This symbol represents the ATEX 114 directive

ATEX 153 guideline - former ATEX 137 guideline - describes which safety requirements must be met by employers so that employees can work safely and healthily with explosion hazards. To this end employers must meet certain obligations:

• Employees must be trained to work in explosive environments
• Installations and machines must be inspected, maintained and installed by employees responsible for the installation.
• In areas where there is a risk of explosion it must be indicated which explosive substances are present and their quantities
• Hazardous areas must be classified into ATEX zones

Explosion hazardous areas are indicated with the following triangle:

This symbol represents the ATEX 153 directive

Under the ATEX 153 guideline employers are required to divide hazardous areas into ATEX zones. These zones must be included in a safety document. The explosion risks are determined on the basis of a risk inventory and evaluation. The ATEX-114 approved equipment is divided into categories, which indicate in which zones they may be used.

• The zones with a gas or vapor explosion hazard are referred to as zone 0, 1 or 2.
• The zones with a dust explosion hazard are indicated as zone 20, 21 or 22.

To get the correct zone division various factors and components are taken into account.

• The hazard sources - all points where gas, vapor or dust can be released - are mapped;
• The quantities of gas, vapor and dust that could be released in the area are calculated;
• The probability is calculated that a dangerous explosive mixture is present.

For a final zone classification it is examined how often an explosive mixture can arise. The zone division looks like this:

ATEX directive is not a safety standard. The ATEX directive indicates which requirements companies must adhere to when working in potentially explosive areas. Such as which safety clothing should be worn. Clothing that is certified according to the EN 1149 standard meet the requirements of the ATEX directive.