For Chinese enterprises expanding overseas into sectors like chemicals, oil and gas, or mining, one category of equipment is unavoidable: explosion-proof electrical
equipment. During procurement and customs clearance, two terms frequently arise—ATEX and IECEx. Many engineers conflate the two, or mistakenly assume that
"having IECEx certification is sufficient for entry into the EU." Such misconceptions often lead to months of project delays and hundreds of thousands in redundant
testing costs.
Today, ESPE will clarify how to make the right choice by breaking down both systems and explaining how they relate to one another.
I. What is ATEX?
The term "ATEX" is derived from the French phrase "Atmosphères Explosibles" (explosive atmospheres). Strictly speaking, the EU’s ATEX framework consists of two
separate directives; what is commonly referred to as "ATEX certification" in engineering contexts actually pertains to only one of them.
Directive 2014/34/EU (the "equipment" directive) governs products: manufacturers must complete a conformity assessment and affix both the CE mark and the "Ex"
mark before the equipment can be placed on the EU market. This directive replaced the earlier 94/9/EC, effective April 20, 2016.
Directive 1999/92/EC (the "user" directive) governs operational sites: employers are required to classify hazardous areas, prepare an Explosion Protection Document
(EPD), and select equipment appropriate for each specific zone.
In short, one directive regulates whether equipment can be sold, while the other governs how it is used on-site. Recently, many project owners in overseas ventures
have begun citing both directives in their tender documents. A common cause for project rework is focusing solely on the equipment itself, only to encounter
obstacles during on-site acceptance due to missing EPDs or hazardous area classification drawings.
Key characteristics of Directive 2014/34/EU include:
First, it is mandatory. Any electrical or non-electrical equipment, protective systems, safety and control devices, as well as components essential to the safe
functioning of such equipment (even if they lack an independent function), intended for use in potentially explosive atmospheres must undergo a conformity
assessment and bear both the CE mark and the hexagonal "Ex" mark. Failure to comply prohibits these items from entering the EU and EEA markets.
Second, there is a classification system based on equipment categories and protection levels, determined by the hazard level of the operating environment:
Group I: Mining (environments containing firedamp and/or combustible dust) — Categories M1 and M2.
Group II: Non-mining environments with explosive gases — Categories 1, 2, and 3.
Group III: Non-mining environments with explosive dust — Categories 1D, 2D, and 3D.
The corresponding Equipment Protection Levels (EPLs) are: Ma and Mb for Group I; Ga, Gb, and Gc for Group II; and Da, Db, and Dc for Group III.
A common misconception is to assume that "Group II" encompasses all non-mining applications. In fact, dust-related environments constitute a separate category,
denoted by the suffix "D." This is a crucial change introduced in Directive 2014/34/EU (replacing 94/9/EC) that is frequently overlooked. Companies that only certify
their equipment for Group II will find their bids rejected during the technical evaluation phase if the project involves dust-laden environments.
Third, the conformity assessment procedure varies according to the risk level. The Directive’s annexes outline specific assessment pathways for different categories,
the primary distinction being whether the involvement of a Notified Body (NB) is required.
The final point is critical: for Category 3 equipment (intended exclusively for use in Zone 2 or Zone 22), manufacturers may issue a self-declaration of conformity
without engaging a Notified Body. Conversely, equipment intended for Zone 0 or Zone 1 must undergo EU-type examination and an audit of the manufacturer's
quality management system by a Notified Body.
In practice, a common source of inefficiency occurs at the other end of the spectrum: submitting an entire tender package—including items that only require
self-declaration—to a Notified Body based on the highest risk level present in the package. Often, more than half of the equipment in such a procurement
package is intended for Zone 2, which could have been handled via self-declaration. Fourth, technical documentation and the EU Declaration of Conformity
must be retained for 10 years from the date the equipment is placed on the market, and must be made available for regulatory inspection at any time.
For companies expanding internationally, ATEX serves as an "entry ticket" to the EU; without it, equipment cannot even clear customs.
II. What is IECEx?
IECEx is a conformity assessment system for explosive atmosphere equipment, established by the International Electrotechnical Commission (IEC) and based
on the IEC 60079 series of international standards. It comprises four parallel schemes; the first is the one most commonly used by enterprises:
IECEx 02: Certified Equipment Scheme
IECEx 03: Service Facility Certification (for repair and overhaul workshops)
IECEx 04: IECEx Conformity Mark Licensing
IECEx 05: Certificate of Personnel Competence (CoPC)
Key characteristics include:
First, while technically voluntary, it has become a de facto mandatory requirement in many countries. Although IECEx is not a legal threshold in itself, it has
become a prerequisite for project access or customs clearance in countries and regions such as Australia, New Zealand, Singapore, Malaysia, the UAE, Saudi
Arabia, and Brazil. In some of these jurisdictions, an IECEx certificate is accepted directly, while in others—such as Brazil—it serves as the foundational
documentation for obtaining local certification (requiring validation and conversion by a local body).
Second, it follows a fixed three-part structure: product testing, factory audit, and ongoing surveillance. This process is carried out by IECEx-recognized Certification
Bodies (ExCBs) and Testing Laboratories (ExTLs). A Quality Assessment Report (QAR) is issued following an audit of the manufacturer’s quality management
system, which is then subject to annual surveillance.
It is important to distinguish between the three types of IECEx documents. Many engineers focus solely on the Certificate of Conformity (CoC), but each of the
three documents serves a specific purpose:
When seeking to convert an IECEx certificate into another certification, it is the ExTR (Test Report) and QAR that are actually reused—not the CoC. This is why
many companies that attempt to apply for other certifications using only a CoC are subsequently asked to provide the ExTR.
Third, it enables "test once, accept in multiple countries." As of December 31, 2025, the IECEx system comprises 36 official member countries (including China),
105 Ex Certification Bodies (ExCBs), and 89 Ex Testing Laboratories (ExTLs). Furthermore, a significant number of non-member countries also accept IECEx
certificates or test reports within their procurement or regulatory practices.
It is important to be precise with the figures: "36 member countries" is the accurate, official statistic. Conflating member countries with countries that merely
accept IECEx documentation to arrive at a larger, combined figure can lead to awkward situations—such as being caught off guard by questions from a project
owner during a tender defense.
Fourth, the information required on an IECEx nameplate is more comprehensive—not less—than that required under ATEX. An IECEx equipment nameplate must
display the full "Ex" marking, including the type of protection (e.g., db, ib, tb), equipment group and category, gas/dust group (IIA/IIB/IIC or IIIA/IIIB/IIIC),
temperature class (T1–T6 or maximum surface temperature), and Equipment Protection Level (EPL: Ga/Gb/Gc, Da/Db/Dc), in addition to the IECEx mark, certificate
number, and serial number.
The common claim that "IECEx only requires an 'Ex' mark and a certificate number" is incorrect. In fact, the technical parameter labeling requirements for an IECEx
nameplate are at least as extensive as—if not more extensive than—those for an ATEX nameplate.
For companies expanding internationally, IECEx serves as a "global passport." While it does not replace the mandatory compliance requirements for the European
Union (ATEX), it significantly reduces the costs associated with redundant product testing and factory audits across different countries.
III. Understanding the Differences Between the Two Systems: A Summary Table
The two systems are essentially aligned regarding explosion-protection principles, temperature classes, Equipment Protection Levels (EPLs), and the classification
of hazardous areas. The EN 60079 series is an identical adoption of the IEC 60079 series, as is China’s GB/T 3836 (formerly GB 3836) series; consequently, they
share the same standards for structural design, clearances, temperature limits, and testing conditions.
The true differences lie in the "market access rules," not in the "technical thresholds." A key clarification: IECEx is not a statutory replacement for ATEX. However,
the two systems are highly aligned in terms of technical standards. Leveraging an IECEx ExTR (Test Report) and QAR (Quality Assessment Report) to facilitate an
ATEX conversion can significantly shorten the certification timeline—provided that any EU-specific deviations are addressed. EN versions of standards include
supplementary requirements unique to the EU; when converting an IEC report for ATEX compliance, these differences must be covered through additional
testing or evaluation.
The common misconception that "having IECEx is sufficient for EU market access" often stems from a failure to adequately address these specific EU requirements.
IV. Selection and Implementation of Equipment for Hazardous Areas: Zone – Category – EPL Correlation
While certification pathways serve as external regulatory hurdles, the actual selection of equipment is dictated by the classification of hazardous areas. The following
table applies to both systems:
EPL (Equipment Protection Level)—a concept integrated into the IEC 60079 series—serves as a common technical language and is currently the least ambiguous
way to specify equipment for international projects. For instance, specifying "Gb" in tender documents is far less prone to misinterpretation across international
project teams than using the "II 2G" designation. Many pieces of equipment manufactured in China only display the older category codes rather than the EPL; this
frequently leads to requests for clarification when such equipment is supplied to projects in the Middle East or Southeast Asia.
Three critical recommendations for project implementation:
Hazardous area classification drawings are a prerequisite, not an afterthought. For international projects, qualified entities must produce these drawings—in
accordance with IEC 60079-10-1 (for gases) or IEC 60079-10-2 (for dusts)—during the basic design phase. Attempting to provide these drawings only after
equipment has arrived on-site often reveals that the equipment’s protection level is insufficient, necessitating the return or replacement of the entire shipment.
Avoid applying the highest protection level to an entire procurement package. Specifying "Zone 1 / Gb" equipment for areas that only require "Zone 2" is wasteful;
conversely, using "Zone 1" equipment in a "Zone 0" area creates a serious safety hazard. Determining the required protection level for each individual piece of
equipment based on its specific zone is the only way to balance cost control with essential safety requirements.
Clearly define the party responsible for certification within the EPC (Engineering, Procurement, and Construction) contract. Will the certification be held by the
equipment manufacturer, or will it be managed on their behalf by the EPC contractor? A discrepancy between the certificate holder and the manufacturer's name
on the equipment nameplate is a common reason for shipments to be held up during customs clearance.
V. ESPE’s Guide for Chinese Enterprises Going Global: Four Pathways
Pathway 1: Focusing Exclusively on the EU Market – ATEX. This is a mandatory requirement; products can be placed on the market by affixing the CE and Ex marks,
with no need for additional, indirect routes. For destinations in Ireland or Northern Ireland, CE/ATEX certification remains applicable.
Pathway 2: Projects in the UK (England, Wales, and Scotland) – UKEX + UKCA. Following Brexit, the UK established its own independent legislation—the Equipment
and Protective Systems Intended for Use in Potentially Explosive Atmospheres Regulations 2016* (UKSI 2016/1107, as amended by 2019/696 and others).
Compliance requires a UK-type examination certificate—commonly referred to in the industry as "UKEX"—issued by a UK Approved Body, accompanied by
the UKCA mark.
Important recent update: The UK government has announced an indefinite extension for the recognition of products that meet EU requirements (including those
bearing the CE mark). This was formalized via the *Product Safety and Metrology etc. (Amendment) Regulations 2024*, which took effect on October 1, 2024. A "
Fast-Track UKCA" route has also been introduced, allowing assessment procedures already completed for the CE mark to be credited toward UKCA compliance.
However, legally, ATEX and UKEX remain distinct regulatory frameworks. Before undertaking a project in the UK, it is essential to verify the specific requirements
of the project owner and customs authorities; do not assume that ATEX certification is universally accepted. Northern Ireland continues to follow EU regulations.
Pathway 3: Global Multi-Region Strategy – Leveraging IECEx. This is the most cost-effective approach: a single round of testing can be utilized across multiple
countries. Based on the ExTR (Ex Test Report) and QAR (Quality Assessment Report), manufacturers can obtain local certifications for various markets. Key
conversion rules for major markets include:
Pathway 4: Projects in North America – A Completely Separate Approach. This is the path most prone to complications and compliance failures. North America
employs a classification system based on "Classes" (Class I for gases/vapors, Class II for dusts, and Class III for fibers) and "Divisions" (1 and 2). This system is
incompatible with the IEC "Zone" system. Furthermore, requirements for explosion-proof construction, gap dimensions, and enclosures differ, as do the
classification tables for temperature and gas groups. Certifications from UL, CSA, and FM are not mutually recognized with the IECEx scheme.
For Chinese enterprises operating in North America—or working on EPC projects that follow U.S. standards—it is essential to allocate specific budgets and
timelines for NEC/CEC (National Electrical Code/Canadian Electrical Code) certifications. One cannot simply rely on IECEx or ATEX certifications as substitutes.
The criterion for determination is straightforward: check whether the project adheres to IEC/GB standards or NEC/UL standards.
VI. Certification Is Not Merely a Cost; It Is a Passport for Global Market Access
When exporting explosion-proof equipment, the true cost does not lie in the certificates themselves, but in choosing the "wrong path." For instance, obtaining
only an IECEx certificate when ATEX is required can lead to customs clearance issues in the European Union. Similarly, allocating a budget toward IECEx when
North American-specific certification is needed—or procuring equipment at the highest possible safety rating across the board, rather than tailoring ratings
to specific zones—results in unnecessary expenditure.
Understanding the relationship between ATEX, IECEx, UKEX, and the North American system is, in essence, about mapping out a "global passport" strategy
before a project even begins:
The European Union: Requires ATEX (mandatory, though self-declaration is permitted for lower-risk categories).
The United Kingdom: Requires UKEX and UKCA (legally distinct from the ATEX framework).
Global Coverage: IECEx allows for "test once, use many times," though factory audits are generally still required when converting to other regional certifications.
North America: Operates under the Class/Division system, which is entirely independent and not mutually recognized by the IEC framework.
Only by integrating these four frameworks can a Chinese enterprise develop a comprehensive compliance roadmap for exporting explosion-proof equipment.
Any missing component will inevitably resurface as a setback—manifesting as delays or additional costs during customs clearance or on-site project acceptance.
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