What are ATEX and IECEx standards? Cables and accessories for hazardous areas

Explosion risks are a major concern in many industrial environments, requiring a comprehensive risk-management approach. A key element of this approach is the hazardous area classification system, which is essential for establishing strict safety procedures and complying with relevant standards. Proper classification protects both personnel and equipment from the dangers posed by flammable gases, vapors, combustible dust, and easily ignitable fibers.

Two primary standards guide this classification:

• National Electrical Code (NEC – United States): Defines and regulates Hazardous Locations (HAZLOC).
• International Electrotechnical Commission (IEC) Standards: Widely recognized in the United Kingdom, European Union, and many other regions.

In the U.S., these environments are commonly referred to as Hazardous Locations (HAZLOC), whereas in the U.K., EU, and other parts of the world, the more common term is Hazardous Areas.

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1.1 NEC hazardous area classification

The National Electrical Code (NEC), issued by the U.S. National Fire Protection Association (NFPA), is the foundational document that provides detailed guidelines for electrical installations in the United States. NEC classifies hazardous locations using a Class–Division–Group system:

• Classes identify the type of hazardous material: Class I (Flammable gases or vapors), Class II (Combustible dust), Class III (Easily ignitable fibers or flyings).

• Divisions indicate the level of risk:

Division 1: High likelihood of the hazardous substance being present during normal operations

Division 2: Hazardous substance is present only under abnormal conditions

In addition, NEC categorizes hazardous substances into Groups A through G based on ignition temperature, minimum ignition energy (MIE), and flame-propagation characteristics, helping engineers select equipment with the appropriate protection level:

• Group A: Acetylene – extremely low ignition temperature and energy
• Group B: Hydrogen – very low ignition temperature and energy
• Group C: Ethylene – low ignition temperature and energy
• Group D: Methane, Propane – relatively low ignition temperature and energy
• Group E: Metal dusts – variable ignition temperatures and MIE
• Group F: Coal dust – high ignition temperature but low MIE
• Group G: Fibers and flyings – variable flammability characteristics

Operating in high-risk industries requires a deep understanding of international safety standards and certification systems. Among these, ATEX and IECEx are the two leading global frameworks for explosive atmospheres, forming the foundation for both safety and regulatory compliance.

Compliance with either ATEX or IECEx demonstrates a company’s strong commitment to protecting workers and production systems. These certifications are recognized worldwide, serving not only as a legal requirement but also as proof of excellence in explosion protection.

2.1 ATEX standard

ATEX (short for ATmosphères EXplosibles) is a European Union directive that specifies the requirements equipment must meet to be considered safe for use in explosive atmospheres.

This standard applies to both electrical and non-electrical equipment capable of generating an ignition source. ATEX certification confirms that a product is designed and manufactured to the highest levels of explosion-proof safety.

2.2 IECEx standard

The IECEx (International Electrotechnical Commission System for Certification to Standards Relating to Equipment for Use in Explosive Atmospheres) is a global certification system that harmonizes the assessment and management of equipment intended for hazardous environments.
IECEx simplifies international trade by providing a single, globally accepted certification process, ensuring that equipment meets recognized international safety standards.

Electrical cables and accessories with IECEx certification can be sold and used across participating countries without the need for separate national testing or re-certification.
Because individual countries often maintain their own safety requirements, equipment exported from one nation to another typically must undergo additional testing and approval to be used in hazardous areas.

With IECEx, member nations agree on a common set of safety standards, significantly reducing inspection costs and certification time for manufacturers. Participating countries include most of Europe, as well as Canada, Australia, Russia, China, the United States, and South Africa, among others.

5.2 Other cables for use in hazardous areas

• Instrument cables: Installation in hazardous areas acc. to IEC 60079-14 ANNEX E but only with the correct ATEX conform accessories

• HELUDATA® PLTC UL13 PVC/PVC OS 300
• HELUDATA® PLTC UL13 PVC/PVC IOS 300
• HELUDATA® PLTC UL13 XLPE/LS0H OSA 300

• Bus cables: This cable is flame retardant and is designed for usage and installation in cable trays, ducts and / or armored tubes (reinforced tubes) such as Zone 1 & Zone 2 respective IEC 60079-14 ANNEX E, but only using the correct ATEX accessories.

• HELUKAT® O&G Cat.6A F/FTP 4x2xAWG23/1 FRNC/FRNC
• HELUKAT® O&G Cat.7e S/FTP 4x2xAWG23/1 FRNC/FRNC
• HELUKABEL® BUS Cables FOUNDATION™ Fieldbus armoured