What Is ATEX?

From chemical plants to flour mills, from paint workshops to oil filling facilities, in many businesses gas, vapor, mist or dust dispersed in the air in certain proportions can become explosive with a single spark. ATEX is the name of the European Union legislative framework through which this risk is managed. In this article we explain step by step what ATEX means, which directives it consists of, which products it covers, and how it differs from CE marking.

What Does the Word ATEX Mean?

ATEX is an abbreviation derived from the French phrase "ATmosphères EXplosibles" (explosive atmospheres). In everyday use, it refers both to the relevant EU directives and, more broadly, to all the equipment, processes and certification activities covered by those directives. An explosive atmosphere is a mixture, under atmospheric conditions, of a flammable substance with air, in such a proportion that once ignition occurs, combustion spreads to the entire unburned mixture.

ATEX Legislation Consists of Two Separate Directives

The term ATEX actually covers two different, complementary EU directives, and the two address different parties:

The area SAFETEST provides consultancy for is primarily equipment conformity under 2014/34/EU — in other words, the process of designing, testing and certifying your product, as a manufacturer, so that it carries the Ex mark. Zone classification on the workplace side, on the other hand, is a separate assessment carried out on a facility basis, under the responsibility of the operating business itself; however, equipment selection is made according to this classification, so the two sides directly affect each other.

Which Products Fall Within ATEX Scope?

2014/34/EU covers the following product groups, designed for use in explosive atmospheres:

• Electrical and mechanical equipment (motors, pumps, lighting fixtures, control panels, sensors)
• Protective systems (explosion suppression systems, explosion venting panels, spark extinguishing systems)
• Safety, controlling and regulating devices (components that contribute to the safety function even if the equipment itself is not Ex)
• Components (parts that do not function on their own but are to be mounted on Ex equipment)

The fundamental criterion determining whether equipment falls within ATEX scope is whether its intended use is an explosive atmosphere; a device designed for a standard office or home environment does not fall within ATEX scope just because it happens to be used in a chemical plant. Determining scope is the most critical step of the process and is closely related to the general logic of determining CE directives; our article Which Directives Apply to My Product? can also be a useful guide here.

Equipment Groups and Categories

2014/34/EU divides equipment into two main groups according to the environment in which it will be used:

• Group I: Equipment used in underground mining operations (with methane and/or combustible dust risk). Divided into Category M1 (highest protection) and M2.
• Group II: Equipment used in surface industries (chemical, petrochemical, food, pharmaceutical, energy, etc.) in an environment of explosive gas, vapor, mist or dust. Divided into Category 1 (highest protection, continuously hazardous areas), Category 2 (medium risk) and Category 3 (low risk); the letter "G" is also added for gas environments and "D" for dust environments (for example, 2G, 3D).

Which category of equipment can be used in which area is directly linked to the zone classification of the area. For gas environments, Zone 0, 1, 2 classification is used; for dust environments, Zone 20, 21, 22 classification is used. You can find our detailed guides on this topic in our articles What Are Zones 0, 1 and 2? and What Are Zones 20, 21 and 22?.

The Relationship Between ATEX and CE Marking

A product within ATEX scope must carry the CE mark, because it is part of general CE legislation; however, this alone is not sufficient. The product must also carry its own specific "Ex" marking — additional labeling showing the equipment group, category, protection type, gas/dust group and temperature class. We explain how to read this marking, with examples, in our article How Is the Ex Mark Read?.

Overview of the ATEX Process

1. Clarify whether the product's intended use is an explosive atmosphere.
2. Determine the zone classification (0/1/2 or 20/21/22) of the targeted area of use.
3. Identify the equipment group and category required for that zone.
4. Choose the appropriate protection type (Ex d, Ex e, Ex ia, etc.) and the relevant EN/IEC 60079 series standards.
5. Carry out the ignition hazard analysis.
6. Plan notified body involvement for Category 1 and 2 equipment; self-declaration is sufficient for Category 3.
7. Prepare the technical file and complete the required tests.
8. Issue the EU Declaration of Conformity and affix the CE and Ex marks to the product.

If you would like to examine the application and certification steps of the process in more detail, see our article How Is ATEX Certification Obtained?.

Frequently Asked Questions

Conclusion

ATEX is a specialized legislative framework, with stricter requirements than the standard CE process, that ensures equipment used in explosive atmospheres is safely designed and correctly marked. Managing the process correctly is critical both for worker safety and for legal compliance.