IECEx is the international certification scheme for equipment, services, and personnel used in explosive atmospheres. Where ATEX is a regional legal requirement, IECEx is the globally recognized system that lets a single certificate open doors in dozens of countries. For an engineer, it is the passport an Ex-rated device carries around the world. This guide explains how IECEx works and where it fits in oil and gas.
IECEx in one line: IECEx is the IEC System for Certification to Standards Relating to Equipment for Use in Explosive Atmospheres. It provides internationally accepted Certificates of Conformity for Ex equipment based on the IEC 60079 standard series, verified by accredited certification and test bodies. Because many countries recognize IECEx, a single certification supports global acceptance without repeating national testing.
IECEx is a conformity assessment system operated under the International Electrotechnical Commission. It certifies that equipment for explosive atmospheres meets the IEC 60079 series of standards, which define the protection concepts (flameproof, intrinsic safety, increased safety, pressurization, and more), the zone system, gas groups, and temperature classes used worldwide.
The scheme has several parts: certified equipment (the Ex Equipment Scheme), certified services such as repair and overhaul, and certified competency of personnel who work on Ex installations. The equipment scheme is the one most engineers meet, and it issues an internationally recognized IECEx Certificate of Conformity for each certified product.
Certification runs through accredited bodies: an IECEx Certification Body (ExCB) issues certificates based on test reports from an IECEx Test Laboratory (ExTL), and manufacturing is verified through a Quality Assessment Report of the production site. This chain means the certificate reflects not just a good prototype but ongoing production quality.
Every valid IECEx certificate is published in the public online certificate system, so anyone can verify a product's status, ratings, and any conditions of use directly from the source. The certificate spells out the protection concept, gas group, temperature class, and ingress rating, and mirrors the Ex marking on the equipment nameplate. Because the underlying standards are the IEC 60079 series, IECEx and ATEX share the same technical language.
Oil and gas is a global industry, and IECEx exists precisely so an operator in the Middle East, Australia, or Southeast Asia can accept equipment certified once rather than demanding fresh national testing. Many national schemes reference or accept IECEx certificates directly, which streamlines procurement for internationally sourced instruments, motors, and enclosures.
In practice, manufacturers of hazardous-area equipment often hold both IECEx and ATEX certification, plus North American approvals, so one product line serves every market. When selecting field devices for a classified area, an engineer confirms the IECEx certificate covers the correct zone, gas group (IIA, IIB, or IIC), and temperature class for the atmosphere present, exactly as they would with an ATEX or North American listing.
No. IECEx is a voluntary international certification scheme, not a law. ATEX is EU legislation that legally requires certification before equipment can be placed on the European market. Many countries, however, accept or reference IECEx certificates in their own regulations, which gives IECEx broad practical force even though it is not itself a legal mandate.
Every valid IECEx Certificate of Conformity is published in the public IECEx online certificate system. You can look up the certificate number from the equipment nameplate to confirm it is current, see the exact ratings (protection concept, gas group, temperature class, ingress rating), and read any special conditions of safe use. This public verifiability is a deliberate feature of the scheme.
They share the same technical basis, the IEC 60079 standard series, so the zones, protection concepts, gas groups, and temperature classes are the same, and equipment is frequently certified to both. They are not legally interchangeable, though: ATEX is required to sell into the EU market, while IECEx is the international acceptance framework. For a European installation you still need the ATEX certification even if the product also holds IECEx.
Primary references from the standards bodies and regulators that define this topic:
Merobix reads your field devices into a cloud SCADA - the real thing behind these terms, live in days from any browser.