ATEX and IECEx – Frequently Asked Questions

Below you will find answers to frequently asked questions about ATEX, IECEx, explosion-protected equipment and certification.

Can't find the answer to your question? Please feel free to contact MIBEX for technical advice.

• Does ATEX equipment always require certification by a Notified Body?

  No. The applicable conformity assessment procedure depends on the equipment category and type. For Category 3G/3D equipment, manufacturers may independently assess and declare conformity. This also applies to Category 2G/2D non-electrical equipment, provided that the technical documentation is lodged with a Notified Body. For Category 2G/2D electrical equipment and Category 1G/1D equipment, the involvement of a Notified Body is mandatory.

  Further information can be found on our page about ATEX Directive 2014/34/EU and conformity assessment.

• Does mechanical equipment also have to comply with ATEX?

  Yes, if the equipment is intended for use in a potentially explosive atmosphere and has its own potential ignition source. Examples include pumps, fans, mixers and screw conveyors. However, not all mechanical equipment automatically falls within the scope of ATEX Directive 2014/34/EU. For non-electrical ATEX equipment, an Ignition Hazard Assessment is generally performed according to EN ISO 80079-36.

  Read more about mechanical ATEX equipment.

• Does an assembly of ATEX-certified equipment require separate certification?

  Using individually ATEX-certified components does not automatically mean that the complete assembly complies with ATEX Directive 2014/34/EU. Combining equipment may introduce additional ignition hazards, for example through mechanical interactions, heat generation or the combination of protective systems. When the complete assembly is placed on the market as an ATEX assembly, the manufacturer must assess its conformity. Whether a Notified Body must be involved depends on the applicable conformity assessment procedure. The distinction between an assembly and an installation is also important.

  Further information can be found on our page about ATEX and IECEx Design.

• Can I use a standard IP54 enclosure for Ex ec equipment (formerly Ex nA)?

  This may be possible, but an IP54 rating alone is not sufficient to demonstrate compliance with the Ex ec requirements. As part of the complete equipment, the enclosure must comply with the applicable requirements of EN IEC 60079-0 and EN IEC 60079-7. These include temperature resistance, material suitability, thermal ageing tests, mechanical strength and the required degree of protection. A standard enclosure does not necessarily require separate ATEX certification, provided its suitability is demonstrated as part of the conformity assessment of the complete equipment.

  Read more about electrical types of protection.

• Can a machine have different ATEX categories internally and externally?

  Yes. Machines processing potentially explosive substances may be exposed to different explosive atmospheres internally and externally. For example, a machine may be intended for Zone 21 internally (Category 2D, EPL Db), while its external parts must be suitable for Zone 22 (Category 3D, EPL Dc). In such cases, the ignition hazards associated with both sides must be assessed separately. The different protection levels may be reflected in the ATEX marking, for example II 2/3D. The technical documentation and operating instructions must clearly identify the protection level applicable to each part of the machine.

  Further information can be found on our page about ATEX marking.

• What is an Ignition Hazard Assessment (IHA)?

  An Ignition Hazard Assessment (IHA) identifies and evaluates potential ignition sources of non-electrical equipment. The assessment considers ignition hazards such as hot surfaces, friction, mechanically generated sparks and electrostatic discharges during normal operation and malfunctions relevant to the required equipment category. Based on the assessment, the necessary protective measures are determined.

  For mechanical ATEX equipment, EN ISO 80079-36 provides the usual basis for this assessment.

• Why are temperature measurements performed on ATEX equipment?

  Temperature measurements are used to determine the maximum surface temperature and the maximum service temperature of individual components. The maximum surface temperature is relevant to the temperature classification of the equipment. The service temperature is important for assessing the suitability of plastics, seals and other materials, as well as determining the requirements for thermal ageing and impact tests.

  Read more about our ATEX temperature measurements.

• What are the benefits of IECEx certification?

  IECEx is an international certification scheme for electrical and non-electrical explosion-protected equipment. An IECEx certificate is issued by an approved IECEx Certification Body (ExCB) and provides internationally recognised technical evidence of conformity. IECEx certification can simplify the process of obtaining national certifications and approvals. However, an IECEx certificate does not automatically allow equipment to be used in every country without additional requirements.

  Read more about IECEx 02 certification.

• What does Ex h mean for mechanical equipment?

  Ex h is the designation for non-electrical explosion-protected equipment assessed according to EN ISO 80079-36 and, where applicable, EN ISO 80079-37. EN ISO 80079-36 specifies the general requirements and the methodology for performing an Ignition Hazard Assessment. EN ISO 80079-37 describes three types of protection:

  • Constructional safety 'c': preventing effective ignition sources through suitable mechanical design and construction.
  • Control of ignition sources 'b': monitoring critical parameters and taking appropriate action before ignition sources become effective.
  • Liquid immersion 'k': preventing ignition by immersing potential ignition sources in a suitable protective liquid.

  The applied types of protection must be justified in the technical documentation and user manual. The equipment is marked with the general type of protection Ex h.

  Read more about mechanical ATEX equipment and Ex h.

• Does an Ex repair facility need IECEx 03 certification?

  No. IECEx 03 certification is not generally a legal requirement in Europe. However, repair and overhaul of explosion-protected equipment must be carried out in a way that preserves the explosion protection characteristics. IEC 60079-19 specifies the relevant technical requirements and procedures. IECEx 03 enables repair facilities to have their technical competence, procedures and quality management system independently assessed and certified.

  Further information can be found on our page about IECEx 03 certification.

• Do my employees need IECEx 05 certification?

  IECEx 05 is a voluntary international certification scheme for demonstrating personnel competence in explosion protection. Personnel performing work on Ex equipment and installations must have the necessary competence for their specific tasks. IECEx 05 provides a means of independently demonstrating these competencies. Completing a training course or knowledge test does not automatically result in an IECEx Certificate of Personnel Competence (CoPC). A separate competence assessment by an approved ExCB is required.

  MIBEX provides practical ATEX and IECEx training courses.

• When are bearing and temperature monitoring required for ATEX machinery?

  Bearing and temperature monitoring are not mandatory for every ATEX machine. The need for monitoring is determined by the Ignition Hazard Assessment according to EN ISO 80079-36. This assessment considers factors such as bearing design, operating speeds, material combinations and the possibility of overheating or mechanical contact. If a potential ignition source cannot be adequately prevented through constructional measures, monitoring may be necessary. In such cases, the monitoring system must respond in time and provide the reliability required for the applicable protection level. The requirements for control of ignition sources 'b' according to EN ISO 80079-37 may apply.

  MIBEX supports manufacturers with explosion-safe design and the assessment of protective measures.

• Do cables for intrinsically safe (Ex i) circuits always have to be light blue?

  No. Cables used for intrinsically safe circuits must be identifiable, but a light blue outer sheath is not always required. When colour coding is used to identify intrinsically safe circuits, light blue must be used. Depending on the installation, other identification methods may also be acceptable, provided they comply with IEC 60079-14 and prevent confusion with non-intrinsically safe circuits.

• Are ATEX-certified cables available?

  Ordinary passive electrical cables generally fall outside the scope of ATEX product certification. Therefore, a separate ATEX certificate is normally not required for the cable itself. However, this does not mean that every cable is suitable for use in a potentially explosive atmosphere. IEC 60079-14 specifies requirements for the selection, characteristics and installation of cables. Cable glands and cable entry systems must also comply with the requirements of the applicable type of protection.

• What are the maximum permitted process and cleaning temperatures for ATEX equipment?

  The maximum permitted process and cleaning temperatures depend on the equipment design, temperature classification and materials used. The assessment must establish the maximum surface temperatures resulting from both process heat and any heat generated by the equipment itself. Components such as seals, plastics and bearings must also be suitable for the applicable service temperatures. A cleaning temperature higher than the normal process temperature is not automatically permitted. This depends on the equipment's design limitations and the explosion protection conditions during cleaning. The permitted process and cleaning temperatures must therefore be clearly specified in the technical documentation and operating instructions.

  Read more about ATEX temperature measurements.

• Is a NEN 3140 inspection sufficient for an electrical installation in a hazardous area?

  No. A NEN 3140 inspection focuses on general electrical safety and does not automatically cover all explosion protection requirements. Additional requirements from the IEC 60079 series apply to electrical installations in potentially explosive atmospheres. The initial inspection of new Ex installations is covered by IEC 60079-14. IEC 60079-17 applies to the inspection and maintenance of existing installations.

• What does the letter X after an Ex certificate number mean?

  The letter X following an ATEX or IECEx certificate number indicates that Specific Conditions of Use apply. These conditions are necessary to ensure that the equipment remains explosion-safe in its intended application. Examples include restrictions on ambient temperature, protection against mechanical impact, electrostatic charging or specific installation requirements. The conditions are specified in the certificate and must be included in the operating instructions where applicable.

  An X does not mean that the equipment is less safe, but that additional conditions must be observed.