North America, IECEx vs ATEX

When it comes to hazardous location safety, North America and Europe have established rigorous certification systems to ensure the safety of equipment used in environments with explosive atmospheres. However, the certification processes, standards, and terminology differ significantly between these regions. In Europe, the ATEX directive is also a key regulatory framework. Here’s an overview of the key differences:

Certification Systems

1. North American Certification (NEC, CEC)

   • In North America, hazardous locations are governed by the National Electrical Code (NEC) in the United States and the Canadian Electrical Code (CEC) in Canada. These codes classify hazardous areas using a system of Classes, Divisions, and Groups.

   • Certification bodies like UL (Underwriters Laboratories), FM (Factory Mutual), and CSA (Canadian Standards Association) conduct testing and certification based on these standards.

2. European IECEx Certification

   • Europe follows the IECEx (International Electrotechnical Commission System for Certification to Standards Relating to Equipment for Use in Explosive Atmospheres) system, which is also widely accepted in many countries outside of Europe.

   • The IECEx system uses a Zone classification system and aligns with the international standards of the IEC 60079 series. Certification is carried out by approved bodies, known as ExCBs (Ex Certification Bodies).

3. ATEX Certification (European Union)

   • The ATEX (Atmosphères Explosibles) directive is a legal framework for controlling explosive atmospheres and ensuring the safety of equipment and workers in the European Union.

   • The ATEX directive encompasses two EU directives: Directive 2014/34/EU (equipment and protective systems) and Directive 99/92/EC (workplace safety).

   • ATEX certification is mandatory for equipment used in explosive atmospheres within the EU, and it is based on the same Zone classification system as IECEx but has its own marking and documentation requirements.

Classification of Hazardous Areas

1. North America

   • Classes and Divisions:

     • Class I: Gases, vapors.

     • Class II: Dusts.

     • Class III: Fibers and flyings.

     • Division 1: Hazard is present under normal conditions.

     • Division 2: Hazard is present only under abnormal conditions.

   • Groups: Equipment is further classified into groups (A, B, C, D for gases; E, F, G for dusts) based on the specific type of hazardous material.

2. Europe (IECEx and ATEX)

   • Zones:

     • Zone 0: Gases or vapors continuously present or for long periods.

     • Zone 1: Gases or vapors likely to occur in normal operation.

     • Zone 2: Gases or vapors not likely to occur in normal operation, or if they do, are present for a short period.

     • Zone 20, 21, 22: Similar zones exist for dust hazards.

   • Groups: Equipment is grouped into Group I (mining) and Group II (non-mining), with further subdivisions for specific types of gases and dusts.

   • ATEX: Under ATEX, equipment is categorized into Category 1, 2, and 3 depending on the level of protection and suitability for Zones 0/20, 1/21, or 2/22, respectively.

Protection Concepts and EX Codes

In hazardous locations, various protection methods are used to prevent ignition sources from causing explosions. Here are the key protection concepts along with their corresponding EX codes:

1. Increased Safety - Ex e

2. Type -n Protection (Non-sparking, Limited energy, Restricted breathing, Enclosed break) - Ex nA, Ex nL, Ex nR, Ex nC

3. Intrinsic Safety - Ex ia, Ex ib, Ex ic

4. Purge/Pressurized Protection - Ex pxb, Ex px, Ex py, Ex pz

5. Encapsulation - Ex m, Ex ma, Ex mb

6. Flameproof Protection - Ex d

7. Oil Immersion - Ex o

8. Sand/Powder (Quartz) Filling - Ex q

9. Special Protection - Ex s

10. Optical Radiation Protection - Ex op pr, Ex op is, Ex op sh

Testing and Certification Process

1. North America

   • Certification is typically performed by organizations like UL, FM, or CSA, which test equipment to ensure it meets the requirements of the NEC or CEC.

   • The certification process involves testing to specific standards, followed by periodic inspections to maintain certification.

2. Europe (IECEx)

   • The IECEx certification involves a harmonized global approach. Equipment is tested against the IEC 60079 series standards by an ExCB.

   • The process includes an IECEx Certificate of Conformity (CoC), which can be used internationally, and involves quality assessments and on-site audits.

3. ATEX

   • ATEX certification is required for products intended for use in explosive atmospheres within the European Union. Equipment must comply with the ATEX directive 2014/34/EU.

   • Certification is conducted by notified bodies, and the equipment is marked with the CE marking along with specific ATEX codes indicating the protection concept, group, category, and suitability for specific zones.

   • The certification process includes rigorous testing, documentation (such as the EC Declaration of Conformity), and compliance with both technical and legal requirements.

Conclusion

While the North American NEC/CEC, European IECEx, and ATEX certification systems all aim to ensure safety in hazardous locations, they differ in classification methods, protection concepts, and certification processes. Understanding these differences is crucial for companies operating in or supplying to global markets, as compliance with the appropriate standards is essential for safety, regulatory approval, and market access.