ATEX vs IECEx — What's the Difference?
When working with Ex equipment you will encounter two certification systems — ATEX and IECEx. Both certify that equipment meets the IEC 60079 technical standards, but they operate through different schemes and are recognised in different markets. Understanding the difference is important for equipment selection, inspection, and CompEx assessment preparation.
ATEX — The European and UK System
ATEX stands for ATmosphères EXplosibles. In the EU, ATEX refers to Directive 2014/34/EU, which mandates that equipment intended for use in explosive atmospheres must be certified by a Notified Body and carry the ATEX marking. In the UK post-Brexit, the equivalent is the UK EX (UKEX) marking under the Equipment and Protective Systems for Use in Potentially Explosive Atmospheres Regulations 2016 (as amended).
ATEX equipment carries the distinctive Ex in a hexagon symbol, followed by the equipment group, category, and the specific protection type marking.
IECEx — The International System
IECEx is an international certification scheme operated by the International Electrotechnical Commission. It provides a single certificate recognised in over 50 countries worldwide. IECEx certificates are increasingly preferred for equipment sold into multiple international markets. IECEx equipment carries the IECEx logo and certificate reference.
Which Do You Need?
| Situation | Certification Required |
|---|---|
| Equipment for UK sites (post-Brexit) | UKEX or ATEX (transitional arrangements apply) |
| Equipment for EU sites | ATEX (CE marked) |
| Equipment for international sites | IECEx (most widely recognised globally) |
| Offshore UKCS installations | UKEX / ATEX depending on operator requirements |
When inspecting Ex equipment, verify that the certificate is current and applicable to the area where the equipment is installed. An ATEX certificate for Zone 1 IIB equipment is not valid for use in a Zone 0 or IIC area. The certificate reference, gas group, temperature class, and EPL must all match the area classification where the equipment is installed.
After Brexit — ATEX in the UK
Equipment certified under ATEX before the end of the Brexit transition period continues to be valid in the UK under transitional arrangements. New equipment placed on the UK market from 1 January 2021 should carry the UKEX marking, although the technical requirements remain aligned with ATEX/IEC 60079. In practice, many manufacturers supply dual-certified ATEX/UKEX equipment. Check with your operator for their specific requirements.
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