US What ATEX covers
ATEX is the European Union framework for equipment and workplaces where an explosive atmosphere can form, from flammable gas, vapor, mist or combustible dust mixed with air. The name comes from the French ATmosphères EXplosibles. It is made up of two directives, one aimed at the people who make equipment and one at the people who run the sites where it is used.
Explosive atmospheres turn up in more places than most people expect: refineries and chemical plants, but also paint shops, distilleries, grain stores, flour mills, wastewater works, pharmaceutical plants and battery rooms. Any electrical device used there is a possible source of ignition, through a spark, an arc or a hot surface, so ATEX sets rules for both the equipment and the site.
The two ATEX directives
The two directives work as a pair. The site owner decides how hazardous each area is, and the manufacturer proves the equipment is safe for that level of hazard.
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Equipment directive 2014/34/EU. Sometimes called ATEX 114. It sets essential health and safety requirements for equipment and protective systems placed on the EU market for use in explosive atmospheres, and decides how they are certified and marked.
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Workplace directive 1999/92/EC. Sometimes called ATEX 153. It requires employers to assess explosion risks, classify hazardous areas into zones, select equipment of the right category for each zone and record it all in an explosion protection document.
How to read an ATEX marking
An ATEX marking tells you where a product can be used. For example, II 3G means equipment group II (surface industries), category 3 (suitable for Zone 2) and G for gas. The marking continues with the protection method, gas group and temperature class, such as Ex ic IIC T4 Gc. The table decodes a typical marking for a Zone 2 computer.
| Part of the marking | Example | What it means |
|---|---|---|
| Ex hexagon | Ex in a hexagon | Specific marking for explosion protection under ATEX |
| Equipment group | II | Surface industries; group I is underground mining |
| Equipment category | 3 | Suitable for Zone 2 or 22; category 2 suits Zone 1, category 1 suits Zone 0 |
| Atmosphere | G | Gas, vapor or mist; D means dust |
| Protection concept | Ex ic | Intrinsic safety at level c; others include d (flameproof), e (increased safety) and p (pressurised) |
| Gas group | IIC | The most easily ignited gases such as hydrogen; IIB covers ethylene and IIA propane |
| Temperature class | T4 | Maximum surface temperature of 135 °C |
| Equipment protection level | Gc | Gas, enhanced protection level suitable for Zone 2 |
Temperature classes run from T1 (450 °C) to T6 (85 °C). The class has to sit below the ignition temperature of every substance on site, so a lower maximum surface temperature, a higher T number, suits more substances.
How ATEX certification works
Certification depends on the category. Category 1 and 2 equipment, for Zones 0, 1, 20 and 21, needs an EU type examination by a notified body, an independent test house appointed under the directive. Category 3 equipment for Zones 2 and 22 can usually be self-declared by the manufacturer under internal production control, against the harmonized EN IEC 60079 standards.
Either way, the manufacturer issues an EU declaration of conformity and marks the product. In Great Britain, the same system continues as UKEX under the UKCA marking, and the workplace side is implemented through the DSEAR regulations. Internationally, the IECEx scheme certifies to the same IEC 60079 standards and is accepted in many countries outside Europe.
Who is responsible for what
ATEX spreads the duties across everyone who touches the equipment, and a gap at any stage can undo the others.
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Manufacturers. Design, certify and mark the equipment under 2014/34/EU, and supply instructions that state the conditions of safe use.
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Employers and site owners. Classify the zones, choose equipment of the right category and keep the explosion protection document up to date under 1999/92/EC, or DSEAR in Great Britain.
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Installers. Install to EN IEC 60079-14, which covers cable glands, earthing, segregation of intrinsically safe circuits and the paperwork that proves it.
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Maintainers. Inspect and maintain to EN IEC 60079-17. In the USA, technicians often hold CompEx competence certification for this work.
Choosing equipment for an ATEX area
Selecting a computer or display for an ATEX site follows the same steps every time.
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Classify the area. The site owner assesses how often an explosive atmosphere is present and marks out the zones.
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Match the category. Category 1 equipment suits Zone 0 or 20, category 2 Zone 1 or 21, category 3 Zone 2 or 22.
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Check gas group and temperature. The gas group and T class must suit the substances on site.
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Keep certification intact. Modifying certified equipment can invalidate its marking, so cables, accessories and mounting must follow the certificate.
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Plan for North America separately. North America uses a different system of classes and divisions; our Class 1 Division 2 explainer covers it.
Quick answers on ATEX
ATEX: common questions
What does ATEX stand for?
ATmosphères EXplosibles. It is French for explosive atmospheres, the name of the EU directives that cover them.
Is ATEX certification mandatory?
In the EU, yes. Equipment placed on the EU market for use in explosive atmospheres must meet directive 2014/34/EU. Great Britain requires UKEX marking for the same purpose.
What is the difference between ATEX and IECEx?
Legal requirement versus international scheme. ATEX is EU law. IECEx is a voluntary international certification scheme built on the same IEC 60079 standards, and is accepted in many countries outside Europe.
Are ATEX and Class I Division 2 the same?
No. They are separate approvals. ATEX Zone 2 and Class I Division 2 cover similar risks, but one does not imply the other.
Is a normal computer allowed in an ATEX zone?
No. Only equipment certified for the zone, gas group and temperature class may be installed. Standard computers belong in the safe area or a control room.
Our hazardous area panel PCs include ATEX Zone 2 and Class I Division 2 models, and our intrinsically safe computers cover more demanding areas. The wastewater HMI case study shows one in service. We integrate and validate each system as standard, keeping within the certified configuration.