What ATEX certification is
ATEX certification is the formal process by which a manufacturer demonstrates that electrical or mechanical equipment meets the requirements of the ATEX Product Directive (2014/34/EU in the EU; UKEX/UKCA equivalent in Great Britain post-Brexit). It is not a self-declaration process, for Category 1 and Category 2 equipment, independent testing and examination by a recognised third party (a Notified Body) is mandatory.
Certification is product-specific. A manufacturer who holds an ATEX certificate for one enclosure model cannot apply that certificate to a different model, even if the differences appear minor. Each product range requires its own examination and certificate.
The purpose of certification is twofold: to confirm that the design meets the protection requirements, and to provide users and installers with confidence that the equipment will perform as claimed under the conditions stated on the certificate.
The two ATEX Directives
ATEX comprises two distinct Directives with different obligations:
| Directive | Applies to | Obligation |
|---|---|---|
| 2014/34/EU (ATEX Equipment) | Manufacturers and importers of equipment for use in explosive atmospheres | Must certify products before placing on market; apply CE marking; hold technical documentation |
| 1999/92/EC (ATEX Workplace) | Employers with workplaces where explosive atmospheres may form | Must classify zones; produce Explosive Atmosphere Document; ensure certified equipment used in each zone |
A manufacturer selling ATEX enclosures must comply with 2014/34/EU. A refinery using those enclosures must comply with 1999/92/EC. A manufacturer who also operates their own production facility with hazardous areas must comply with both.
Equipment categories
Equipment categories under 2014/34/EU define the required level of protection and the assessment route:
| Category | Zone | Assessment route | Self-certification allowed? |
|---|---|---|---|
| Category 1G (gas) / 1D (dust) | Zone 0 / Zone 20 | EC-type examination + QA by Notified Body | No |
| Category 2G / 2D | Zone 1 / Zone 21 | EC-type examination by Notified Body | No |
| Category 3G / 3D | Zone 2 / Zone 22 | Internal production control (manufacturer) | Yes (with technical file) |
Category 3 equipment (Zone 2) can be self-certified by the manufacturer, provided they hold a Technical File documenting the design and its compliance. A Notified Body is not required for Category 3, but the manufacturer assumes full responsibility for the adequacy of the protection.
The certification process
For Category 1 and 2 equipment, the certification process involves several stages:
- Prototype design and technical documentation, the manufacturer prepares drawings, specifications, material test reports, and an assessment of compliance with the relevant IEC 60079 standard(s)
- Submission to a Notified Body, the technical file and a sample of the equipment are submitted for examination
- EC-type examination, the Notified Body tests the equipment against the requirements of the applicable standard (e.g., IEC 60079-7 for Ex e). This includes mechanical testing, IP testing, temperature rise measurements, and assessment of creepage and clearance distances
- Issue of EC-type examination certificate, if examination is successful, the Notified Body issues a certificate (e.g., Baseefa 09ATEX1234) specifying the conditions of use
- Production quality system, Category 1 requires the manufacturer's quality system to be assessed by the Notified Body. Category 2 requires internal quality control with the Notified Body assessing quality on request
- Application of CE and Ex markings, the manufacturer applies the CE mark and the ⟨Ex⟩ symbol to the product
- Declaration of Conformity, the manufacturer issues a Declaration of Conformity for each certified product range
Role of the notified body
A Notified Body is an independent organisation designated by a member state (or, for UKCA, approved by UKAS) to carry out conformity assessment for regulated products. For ATEX, the principal UK Notified Bodies are Baseefa (Buxton), Sira (Cheshire), CML (Kent), and Bureau Veritas.
The Notified Body's role is to:
- Assess the technical documentation and test the prototype against IEC 60079 standards
- Issue the EC-type examination certificate
- Monitor the manufacturer's quality system (for Category 1)
- Withdraw or amend certificates if non-conformance is discovered
The Notified Body does not certify the installation or the assembly of products, only the product as manufactured. A certified enclosure fitted with non-certified glands is not a certified installation.
What the certificate covers
The EC-type examination certificate specifies precisely what is covered. Reading the certificate carefully is important:
- Description of equipment, the specific models, sizes, and variants that were tested
- Protection concept and gas/dust group, the standards to which the equipment was tested (e.g., Ex eb IIC)
- Temperature class, the maximum surface temperature class (T1–T6) or specific temperature
- Ambient temperature range, the range within which the equipment maintains its protection; outside this range, the protection may not be guaranteed
- Specific Conditions of Use, if present, marked 'X' on the certificate; these conditions must be complied with for the certification to be valid
- Schedule, lists all sizes, materials, and variants covered
Ongoing obligations
Certification is not a one-time exercise. Ongoing obligations include:
- Surveillance audits, Notified Bodies conduct periodic audits of manufacturers' quality systems
- Change notifications, any change to the certified product design must be notified to the Notified Body; some changes require re-examination
- Market surveillance, national authorities (in the UK, the HSE) conduct market surveillance and can withdraw certificates for non-compliant products
- Document retention, technical documentation must be retained for 10 years after the last product is manufactured
Common misconceptions
Misconception: ATEX certification means the product is safe in all hazardous areas. Certification confirms the product meets the stated standard under the conditions on the certificate. A T4 product is not safe in a zone where the gas has an ignition temperature below 135 °C; an IIA product is not safe in an IIC zone.
Misconception: CE marking means ATEX certification. CE marking indicates compliance with the relevant Directive (which for ATEX is 2014/34/EU). Without the ⟨Ex⟩ symbol and a Notified Body certificate number, CE marking alone does not indicate ATEX certification.
Misconception: ATEX certification covers the whole installation. Certification covers the product as manufactured. The installation, including gland selection, wiring, and assembly, is the responsibility of the installer. A correctly certified enclosure fitted incorrectly is not a compliant installation.
Misconception: Older equipment without ATEX marking is not safe. Equipment certified before ATEX harmonisation may carry national approval marks (BASEEFA, KEMA, BVS). These remain valid for equipment installed before the Directive came into effect and do not need retrospective ATEX re-certification. New installations and replacements should use current ATEX or IECEx certified products.