How to Read an Ex Certificate — Step by Step

An Ex certificate is the formal document that certifies a piece of equipment meets the relevant IEC 60079 requirements. Every piece of Ex equipment should have a certificate — either an ATEX certificate (from a European Notified Body) or an IECEx certificate (from an IECEx body). Understanding how to read a certificate is essential for equipment selection and inspection.

What Does an Ex Certificate Contain?

A typical ATEX or IECEx certificate includes:

• Certificate number — unique reference (e.g. BAS Ex 12345X for UK, ATEX 16 ATEX 0123 for EU)
• Equipment description — manufacturer, model number, and description
• Equipment marking — the full ATEX/IECEx marking string (e.g. II 2 G Ex d IIB T4 Gb)
• Special conditions of use (if any) — marked with "X" suffix on the certificate number
• Technical documentation reference — drawings, specifications on file with the certifying body
• Applicable standards — which IEC 60079 parts the equipment was tested against
• Certifying body — the Notified Body or IECEx body that issued the certificate
• Issue date and validity — certificate status

Reading the Equipment Marking on the Certificate

The equipment marking string is the most important element for selection and inspection verification. For example: II 2 G Ex d IIB T4 Gb

• II — Group II (surface industry, not mining)
• 2 G — Category 2, gas atmosphere (Zone 1 suitable)
• Ex d — flameproof protection, IEC 60079-1
• IIB — suitable for IIA and IIB gas groups
• T4 — maximum surface temperature 135°C
• Gb — EPL Gb, suitable for Zone 1 and Zone 2

Special Conditions of Use — The X Suffix

If a certificate number ends in X, the equipment has special conditions of use that must be observed. These conditions are listed in the certificate and often appear on the equipment label. Common examples include restrictions on ambient temperature range, requirements for specific cable types, or limitations on the types of entries that can be used.

How to Verify a Certificate is Current

ATEX and IECEx certificates can be verified online through the ATEX Notified Body databases or the IECEx system database (iecex.iec.ch). A certificate may be superseded (replaced by a newer version) or withdrawn — always check the current status before relying on an old certificate copy.