What should procurement check on an Ex certificate before buying?
Abstract
Check that the certificate is genuine and current, names the supplier's manufacturer and the exact model and options, gives a marking that fits the zone, gas or dust group, temperature class and ambient range, lists acceptable standards, and has X conditions the site can meet.
Procurement should check two things: that the certificate is real, and that it fits the purchase. Real means current in the IECEx online system or confirmed by the ATEX notified body, and issued for the manufacturer who will supply the goods. Fitting means it covers the exact model and options ordered, its marking suits the zone, group, temperature class and ambient temperature of the site, it lists standard editions the project accepts, and its specific conditions of use can be met on site.
Short answer
- Genuine and valid: an IECEx certificate is Current online; an ATEX certificate or quality notification is confirmed by a notified body that is listed for Directive 2014/34/EU.
- Same product: manufacturer, manufacturing site, type code and every option ordered appear on the certificate (in the issue you rely on).
- Right protection level: equipment category or EPL for the zone (Zone 1 needs category 1 or 2, EPL Ga or Gb), gas or dust group at least as demanding as the area, temperature class below the ignition temperature of the substances present.
- Right environment: marked ambient temperature range and IP rating cover the site.
- Conditions: an X suffix means specific conditions of use, which the site must be able to meet. A U suffix means a component, not equipment ready to install.
- Documents supplied: EU declaration of conformity, instructions in the users' language, and the certificate with all its pages.
Checklist for the purchase file
| Check | What to compare | Typical problem |
|---|---|---|
| Status | IECEx online status Current; notified body listed under 2014/34/EU and confirms the certificate | PDF only, never checked at source |
| Certificate holder and manufacturer | Name and manufacturing location on the certificate against the supplier and the factory | Reseller's own brand on another maker's certificate |
| Model and options | Type code, variants, accessories, cable entries, enclosure size, ratings | Option "-L" ordered, only "-S" and "-M" certified |
| Category or EPL | Zone 0: category 1, Ga; Zone 1: category 1 or 2, Ga or Gb; Zone 2: category 1, 2 or 3; same for Zones 20, 21, 22 with D / Da, Db, Dc | Category 3 item bought for a Zone 1 area |
| Group | Gas: IIC covers IIB and IIA, IIB covers IIA. Dust: IIIC covers IIIB and IIIA | IIB+H2 bought for an acetylene area |
| Temperature class or maximum surface temperature | T-class below the autoignition temperature of every gas present; for dust, maximum surface temperature with the margins IEC 60079-14 requires | T3 equipment for a substance that needs T4 |
| Ambient range | Marked range covers the site's coldest and hottest conditions. Without a marked range, older equipment is rated for the normal range of -20 to +40 °C; IEC 60079-0 edition 8 (2026) requires the range always to be marked | Normal range on equipment for a desert or arctic site |
| Standards | Standards and editions listed meet the project specification | Specification demands a recent edition the certificate does not list |
| Specific conditions (X) | Each condition can be met by design, installation or operation | Condition only found after installation |
| Component (U) | Only bought as part of equipment that will be certified as a whole | Ex component installed on its own |
| Documents | Declaration of conformity names the standards and, where relevant, the notified body and certificate number; instructions in the right language | Instructions missing or only in a foreign language |
Checks that buyers most often skip
The exact variant. A certificate usually covers a family of products with a type code key. The ordered code must decode fully within that key. Options added by the supplier, such as a different gland, window or terminal, must be either on the certificate or certified separately for that use.
Which issue applies. IECEx certificates are reissued when products or standards change, and the scheme states that a new issue does not cancel the earlier ones. Find the issue that lists your variant and check that it is Current.
The X conditions. They are part of the certificate and can affect the whole installation: an impact-protected location, a maximum cable length, a minimum or maximum ambient temperature, earthing details, an electrostatic warning, a fuse rating. Send them to the design engineer before the order is placed, not after delivery.
Standard editions. Under the IECEx rules, new certificates are issued to the current edition of a standard or the one before it, but older certificates stay valid without updating. If a project specification calls for particular editions, check the list on the certificate rather than assuming.
The market. An IECEx certificate does not place a product on the EU market. ATEX requires the CE marking, the declaration of conformity and the conformity procedure for the category. Other markets have their own schemes. The certificate must match the country of installation. For ATEX category 3 equipment and non-electrical category 2 equipment there is no EU-type examination certificate at all: the evidence is the manufacturer's EU declaration of conformity, which for non-electrical category 2 should name the notified body holding the technical file. If the project wants third-party evidence for such items, it must ask for it in the specification.
Example: A buyer is offered a flameproof junction box for a Zone 1, IIB, T3 area at a coastal site where winter temperatures fall to -30 °C. The certificate is Current and marked II 2 G Ex db IIC T6 Gb, which more than covers group and temperature. But it gives an ambient range of -20 to +40 °C, and its X condition requires an external cover for outdoor use. The buyer asks the manufacturer for a low-temperature variant certified to -40 °C and adds the cover to the order. Both points would otherwise have come up at the site inspection.
Common mistakes
- Checking the certificate, not the product. A genuine certificate for a different variant does not cover the item ordered.
- Taking "IIC T6" as always the safe choice. It covers group and temperature, but not the zone, the ambient range, the IP rating or the X conditions.
- Accepting a component as equipment. A U certificate is not enough to install the item.
- Archiving only page 1. The schedule, variants and conditions are on the later pages.
Related on excodex
- How to verify that an Ex certificate is genuine
- The ATEX Declaration of Conformity and the CE and Ex marking: what must be on the label
- The X and U suffixes on Ex certificates: specific conditions of use and Ex components
- How do I check whether an IECEx certificate is valid online?
- Tool: Ex marking check
Standards and further reading
- IEC 60079-0, explosive atmospheres: general requirements for equipment (marking, X and U, ambient temperature).
- IEC 60079-14, design, selection and installation of electrical installations (selection by EPL, group, temperature class).
- Directive 1999/92/EC, Annex II Part B (equipment categories per zone): legislation.gov.uk
- Directive 2014/34/EU, Article 6 (manufacturer obligations, instructions in the users' language) and Annex X (declaration of conformity): legislation.gov.uk
- IECEx FAQ on the certified equipment scheme (status, issues, editions): iecex.com
- European Commission, ATEX 2014/34/EU Guidelines, 6th edition (January 2026): Guidelines PDF
This article is general technical information prepared by the excodex editorial team. It does not replace the applicable standards, the equipment certificates and instructions, national regulations or the assessment of a competent person.