ATEX vs IECEx: What Is the Difference?

What is the difference between ATEX and IECEx?

ATEX is EU law: under Directive 2014/34/EU, equipment for explosive atmospheres must meet the directive's essential requirements and carry the CE marking and the Ex hexagon before it can be placed on the EU/EEA market (see the full ATEX Directive guide). IECEx is a voluntary international certification system run by the IEC, whose certificates are accepted directly or used as the basis for national approval in its 37 member countries. Both test equipment to the same IEC 60079 and ISO/IEC 80079 standards, so one test program can serve both.

The practical differences are:

• Legal status: ATEX is mandatory in the EU/EEA; IECEx is voluntary and only becomes a requirement where a country or a customer specifies it.
• Certificate: ATEX uses an EU-type examination certificate from a Notified Body plus the manufacturer's EU Declaration of Conformity; IECEx issues a Certificate of Conformity (CoC) that is published on iecex.com and backed by a test report (ExTR).
• Third-party involvement: ATEX lets manufacturers self-declare category 3 equipment; IECEx requires independent testing and certification for all equipment, whatever the zone.
• Quality system: ATEX uses a Quality Assurance Notification (QAN) from a Notified Body on the quality assurance routes for category 1 and category 2 electrical equipment; IECEx requires a Quality Assessment Report (QAR) for every certificate.
• Marking: ATEX adds CE, the Notified Body number, the Ex hexagon and the group/category (e.g. II 2 G) to the IEC marking; IECEx adds the IECEx certificate number.

The Essential Difference

ATEX is law. IECEx is not.

If you're selling explosion-protected equipment in the EU, conformity with Directive 2014/34/EU (shown by the CE marking and the EU Declaration of Conformity) is a legal requirement. Outside the EU, IECEx certification is widely recognized but whether it is accepted, and in what form, depends on each country's regulations.

Both systems certify equipment to the same underlying IEC 60079 technical standards. The difference is in the regulatory framework, not the engineering.

What is IECEx?

IECEx is the IEC System for Certification to Standards Relating to Equipment for Use in Explosive Atmospheres. It is operated by the International Electrotechnical Commission; its first meeting was held in 1996. Certification is carried out by approved IECEx Certification Bodies (ExCBs) and Testing Laboratories (ExTLs), which are assessed by their peers against common rules. Every valid certificate is listed in the IECEx On-line Certificate System on iecex.com: if it is not listed there, it is not IECEx certified.

IECEx runs separate schemes:

For how IECEx sits alongside ATEX, UKEX, INMETRO and other national schemes, see Ex certification schemes.

Geographic Scope

ATEX

Applies to:

• All 27 EU member states
• Norway, Iceland, Liechtenstein (EEA countries)
• Switzerland (through the EU–Swiss mutual recognition agreement)
• Northern Ireland, which follows the EU rules
• Great Britain accepts CE-marked ATEX equipment indefinitely alongside its own UKCA/UKEX route (see UKCA Ex certification)

IECEx

Applies to:

• 37 member countries listed on iecex.com, including Australia, Brazil, Canada, China, India, Japan, South Korea, Saudi Arabia, Singapore, South Africa, the UAE, the UK and the USA
• No legal mandate: acceptance depends on each country's regulations
• Some countries accept IECEx certificates directly (Australia and New Zealand are the usual examples); others require national certification that can be issued on the basis of IECEx reports (for example INMETRO in Brazil)
• The USA is a member, but installations follow the NEC and equipment is normally listed by an NRTL; an IECEx certificate alone is not enough

Key point: Many manufacturers pursue both certifications: ATEX for EU sales, IECEx for global markets. Much equipment carries both markings on the same nameplate.

ATEX vs IECEx side by side

Certification Process

ATEX Certification

The conformity assessment route depends on the equipment category (Directive 2014/34/EU, Article 13):

• Category 1 and M1: EU-type examination (Module B) plus either production quality assurance (Module D) or product verification (Module F).
• Category 2 and M2, electrical equipment and internal combustion engines: EU-type examination plus either internal production control with supervised product testing (Module C1) or product quality assurance (Module E).
• Category 2 and M2, other (non-electrical) equipment: internal production control, with the technical documentation sent to a Notified Body, which keeps it.
• Category 3: internal production control (Module A), a self-declaration by the manufacturer.

1. Notified Body: Where a third party is required, the manufacturer selects an EU Notified Body (identified by a four-digit number)
2. EU-type examination: Equipment is tested and assessed against the EHSRs, normally using harmonized EN IEC 60079 standards
3. EU-type examination certificate issued if the product complies
4. Quality Assurance Notification (QAN): issued by the Notified Body after auditing the manufacturer's production quality system (Modules D and E)
5. CE marking: Manufacturer affixes the CE mark (followed by the Notified Body number where that body is involved in production control) and issues the EU Declaration of Conformity

IECEx Certification

1. ExCB (Certification Body): Manufacturer selects an IECEx-approved ExCB from any member country
2. ExTR (Test Report): A sample is tested to the IEC standards by an IECEx ExTL and the results are recorded in an ExTR
3. QAR (Quality Assessment Report): The ExCB audits the manufacturing site's quality system (to ISO/IEC 80079-34) and continues with periodic surveillance audits
4. Certificate of Conformity (CoC) issued once both the ExTR and QAR are satisfactory, and published in the IECEx On-line Certificate System
5. Marking: The equipment carries the IECEx certificate number on its nameplate; the IECEx Conformity Mark is optional and needs a separate license

Mutual recognition: Many Notified Bodies are also IECEx ExCBs, meaning the same organization can issue both certificates from a shared test program.

QAR vs QAN

Both documents confirm that the manufacturer can produce every unit the same as the tested sample. The requirements are the same (ISO/IEC 80079-34, which replaced EN 13980); the difference is who needs one.

An IECEx QAR from any ExCB can be used to support an application for an ATEX QAN.

Can one test report serve both ATEX and IECEx?

Usually yes. An IECEx ExTR from any ExCB can be used to support an application for an ATEX EU-type examination certificate, because apart from the marking the technical requirements are almost always identical. The Notified Body reviews the ExTR, checks that it covers the EN edition harmonized under the directive and any essential requirements the standard does not address, and then issues its own certificate. For category 3 equipment the IECEx certificate and ExTR can go straight into the technical file behind the manufacturer's Declaration of Conformity.

The reverse is less direct: an ATEX EU-type examination certificate is not an ExTR. To get an IECEx CoC, an IECEx ExCB has to issue an ExTR in the IECEx format, although it may draw on existing test data. That is why manufacturers targeting both markets usually start with IECEx testing at a body that is both an ExCB and a Notified Body, and have both certificates issued together.

Equipment Markings

ATEX Marking Example (see also how to read an ATEX nameplate)

CE 1234  ⟨Ex⟩ II 2 G
Ex db IIC T4 Gb
XXX 24 ATEX 1234 X

• CE 1234: CE mark followed by the Notified Body number (only where that body is involved in production control)
• ⟨Ex⟩: the Ex-in-hexagon, the EU "specific marking of explosion protection" (required under ATEX)
• II: Equipment Group (I = mining, II = surface industries)
• 2 G: Equipment Category (2 = suitable for Zone 1 and Zone 2, G = gas)
• Ex db IIC T4 Gb: Technical marking (same as IECEx)
• XXX 24 ATEX 1234 X: EU-type examination certificate number (X = specific conditions of use apply)

IECEx Marking Example

Ex db IIC T4 Gb
IECEx XXX 24.0001X

• Ex db IIC T4 Gb: Technical marking (identical to the ATEX technical portion)
• IECEx XXX 24.0001X: Certificate number (XXX = ExCB code, 24 = year of issue, 0001 = running number, X = specific conditions of use apply)
• There is no Ex hexagon and no category in IECEx marking; the hexagon belongs to the EU system

Note: The technical portion (Ex db IIC T4 Gb) is identical (see Ex markings explained) in both systems because both reference IEC 60079-0. The difference is in the regulatory part: CE, Notified Body number, hexagon and category for ATEX; the certificate number for IECEx. Dual-certified equipment carries both on one nameplate.

Technical Standards: Identical Foundation

Both ATEX and IECEx certify equipment to the same IEC 60079 series of standards:

• IEC 60079-0. General requirements
• IEC 60079-1. Flameproof enclosures (Ex d)
• IEC 60079-11. Intrinsic safety (Ex ia/ib/ic)
• IEC 60079-7. Increased safety (Ex e)
• ISO 80079-36 and ISO 80079-37. Non-electrical equipment (Ex h)
• And further parts covering other protection methods and requirements

In the EU the IEC texts are adopted by CENELEC as EN IEC 60079-x. Once referenced in the Official Journal, they give a presumption of conformity with the directive's essential health and safety requirements. Using them is not strictly mandatory under ATEX, although nearly all manufacturers do; IECEx requires full compliance with the IEC standards. The harmonized EN edition can lag behind the latest IEC edition, so a test report may need a gap check between editions.

In practice, this means:

• An Ex db IIC T4 product has the same technical design whether certified to ATEX or IECEx
• Test procedures are identical (flameproof gap testing, temperature rise testing, fault analysis, etc.)
• Manufacturers can use one IECEx test report for both certification paths

When to Use Each

Get ATEX Certification If:

• You're selling equipment in the EU, EEA, Switzerland or Northern Ireland
• Your equipment will be installed in an EU workplace, where Directive 1999/92/EC requires equipment of the right category for each zone
• You need CE marking for regulatory compliance

Get IECEx Certification If:

• You're targeting markets outside the EU (Australia, the Middle East, Asia, Latin America)
• Your customer requires IECEx certification in their procurement specifications
• You want one certificate and test report that can feed several national approvals

Get Both If:

• You're selling globally
• You want maximum market access with minimal duplication (one ExTR supports both certificates)

Common Misconceptions

"IECEx is the international version of ATEX"

Not quite. ATEX (1994) is an EU legal framework that relies on IEC-based standards; IECEx (1996) is a certification system built directly on the IEC standards. Both are parallel systems addressing the same problem with the same technical foundation.

"You can use an IECEx certificate instead of ATEX in the EU"

No. CE marking under Directive 2014/34/EU is a legal requirement for EU market access, and an IECEx certificate alone does not satisfy EU law. However, an IECEx ExTR and QAR can be used to support the ATEX application.

"ATEX is more strict than IECEx"

Not in technical terms: both use the same IEC 60079 standards. ATEX adds legal obligations (CE marking, conformity assessment modules, market surveillance), while IECEx is stricter in one respect: it requires third-party certification even for Zone 2 equipment that ATEX allows manufacturers to self-declare.

"The US accepts IECEx certificates"

Not on their own. The US is an IECEx member, but installations follow the NEC (Articles 500 to 506) and equipment is listed by NRTLs such as UL, FM Approvals or CSA. Several NRTLs are also IECEx ExCBs and can reuse IECEx test data, but the authority having jurisdiction (AHJ) expects the US listing. See NEC 500 vs ATEX/IEC.

Frequently asked questions

What is the difference between ATEX and IECEx?

ATEX is a European Union directive with legal force in the EU/EEA, while IECEx is a voluntary international certification system run by the IEC. Both use the IEC 60079 standards; they differ in legal status, certificates (EU-type examination certificate vs IECEx CoC), quality documents (QAN vs QAR) and marking.

What is IECEx certification?

IECEx is the IEC System for Certification to Standards Relating to Equipment for Use in Explosive Atmospheres. It certifies Ex equipment (CoC backed by an ExTR and a QAR), service facilities that repair and inspect Ex equipment, and the competence of individual personnel (CoPC).

Can IECEx certification be used instead of ATEX in Europe?

No. IECEx certification alone is not accepted in the EU. However, an IECEx test report (ExTR) and quality report (QAR) can be used to support the ATEX application, since both systems are based on the same IEC 60079 standards.

Can one test report be used for both ATEX and IECEx?

Yes, in most cases. A Notified Body can base an ATEX EU-type examination certificate on an IECEx ExTR after reviewing it against the harmonized EN editions, and the IECEx QAR can support the ATEX QAN.

Which countries accept IECEx certification?

IECEx has 37 member countries, including Australia, Brazil, China, India, South Korea, Singapore, the UK and the USA. Each country's national regulations determine whether an IECEx certificate is accepted directly or used as the basis for a national certificate.

Do ATEX and IECEx use the same technical standards?

Yes, both ATEX and IECEx are based on the IEC 60079 series of standards. The technical requirements are essentially the same, but the certification and marking procedures differ.

Related Topics

• Standards Overview: IEC 60079, ATEX directives, and regional variations
• Certification Process: How products get certified, Notified Bodies, and test reports
• Ex Certification Schemes: ATEX, IECEx, UKEX, INMETRO and other national schemes
• Reading Ex Markings: Decoding the technical portion of ATEX and IECEx nameplates
• Equipment Protection Levels: Understanding Ga/Gb/Gc and how they map to zones