In petrochemical, mining, power, metallurgical, port and dusty environments, combustible gases, vapors or dust can coexist with electrical equipment. A single spark or hot surface can trigger a serious accident. Explosion-proof design is therefore not an optional add-on; it is a core part of the safety system.
Countries and international organizations have established several mature sets of explosion-proof standards. These standards determine the design, selection and application boundaries of industrial explosion-proof telephones.
The three main certification frameworks
IECEx: the global benchmark
The IECEx System, governed by the International Electrotechnical Commission, is the international framework for certifying equipment used in explosive atmospheres. It is widely adopted across Asia-Pacific, the Middle East and South America, and its influence is global.
- Standardization basis: Built on the IEC 60079 series, ensuring technical consistency across borders.
- End-to-end oversight: Unlike systems that focus only on the final product, IECEx audits design, manufacturing processes and ongoing quality management.
- Reciprocal acceptance: Certification in one member country can ease market entry in others, reducing repeated testing.
- Strategic value: For multinational engineering firms, IECEx is often the preferred credential because of its technical rigor.
ATEX: mandatory in the EU
ATEX is the European Union’s mandatory framework for equipment used in explosive atmospheres. It applies to products placed on the European Economic Area market.
- Equipment is classified according to the usage environment and hazard level.
- A risk assessment is required during product design.
- Safety is considered across the equipment’s entire lifecycle.
- Industrial explosion-proof equipment entering the EU, including telephones, generally needs to comply with the ATEX directives.
North America: NEC, UL and FM
North America uses a distinct philosophy for hazardous-area safety, traditionally centered on the Division and Class system, though Zone-based concepts have been integrated in recent years.
- Regulatory pillars: Compliance is driven primarily by the National Electrical Code (NEC), with testing and certification handled by bodies such as Underwriters Laboratories (UL) and FM Global.
- Installation integrity: There is a strong focus on how the equipment interacts with its specific installation environment and on total system protection.
- Industry dominance: These standards are the reference for oil, gas and petrochemical projects across the United States and Canada.
Core technical elements
Whatever certification system is used, explosion-proof standards generally revolve around the same technical questions:
- Explosion-proof type: Flameproof (Ex d), intrinsic safety (Ex i), increased safety (Ex e) and other methods control how ignition sources are contained or prevented.
- Area classification: Zone 0, 1 or 2 (and the corresponding dust zones) describes how often an explosive atmosphere is present.
- Gas and dust grouping: Different media have different ignition energies, so equipment must be matched to the right group.
- Temperature class: The maximum surface temperature of the equipment must stay below the ignition temperature of the surrounding atmosphere.
Common certifications for explosion-proof telephones
- Ex d (flameproof): Contains an internal explosion inside a high-strength enclosure. Suitable for harsh field environments.
- Ex ib / Ex ia (intrinsic safety): Limits circuit energy so that explosive substances cannot be ignited under fault conditions. Common in high-risk areas.
- ATEX, IECEx and local certifications in parallel: Meets access requirements for different countries and projects.
Typical application areas
- Oil refining units, tank areas and pump stations
- Chemical plant reaction workshops and pipe galleries
- Coal mines and coal preparation plants
- Port bulk cargo handling areas and dust-prone work areas
- Metallurgy, power plants and hazardous material storage
Different applications place different demands on explosion-proof rating, IP protection, corrosion resistance and reliability. The nameplate marking is the starting point, not a formality.
Safecom has focused on industrial communication for more than 15 years. Our explosion-proof telephones are built to international standards and can be customized to project requirements.