Choosing the right regulations for safety assessment

Some hazardous industrial environments pose an increased risk of fire and explosion, so equipment must meet the enhanced requirements of applicable regulations and standards. Within the EU, compliance with the ATEX Directive (2014/34/EU) is required, and in other markets the IECEx Equipment Certification Scheme applies. 

The ATEX Directive provides a detailed overview of the essential health and safety requirements applicable to equipment used in hazardous environments. However, the specific technical requirements are found in nearly 100 individual harmonised standards. This means that more than one harmonised standard may be applicable to the evaluation and certification process.

The IECEx Certified Equipment Scheme meets the regulatory requirements of more than 30 countries. It is based on a compliance assessment with the technical requirements found in the IEC 60079 series of standards (electrical products); the IEC 80079 series of standards for non-electrical products; and the application of quality systems which have been developed by Technical Committee (TC) 31.

The ATEX directive’s conformity assessment process provides a certification route for a broad range of equipment. It also offers significant latitude in the technical assessment of non-conventional equipment through the use of a technical construction file.

This can be especially important to manufacturers of customised equipment, or equipment specifically designed for unique applications. However, as the IECEx Certified Equipment Scheme only assesses electrical equipment against TC 31’s IEC standards, this restriction can present an insurmountable hurdle for manufacturers of highly specialised electrical equipment, as relevant standards will not exist.

Under the IECEx scheme, equipment must be tested and certified by IECEx-approved Testing Laboratories and Certification Bodies, and evidence of prior testing conducted by an EU Notified Body is not acceptable. However, EU Notified Bodies located in IECEx member countries are required to accept test reports generated by IECEx-approved testing laboratories in support of an ATEX certification submittal.

Last year the ExTAG and ExNB groups took an unprecedented step forward towards harmonising requirements for both systems

The preferred conformity assessment path for many manufacturers has traditionally involved first obtaining equipment certification under the IECEx Certified Equipment Scheme. IECEx testing data is then be submitted to an EU NB as part of the ATEX certification process

However, last year the ExTAG and ExNB groups took an unprecedented step forward towards harmonising requirements for both systems. ExTAG Decision Sheets (DS) cover mandatory IECEx testing and certification requirements. ExNB is the European equivalent, ensuring that Notified Bodies apply ATEX requirements in a uniform way, and its guidelines are published asClarification Sheets (CS).

ExNB/CS/010 contains a list of 43 approved IECEx ExTAG DS that must now be used in order to comply with the essential health and safety requirements of ATEX Directive. However, this might have grave consequences for equipment manufacturers for whom the IECEx scheme has never been relevant as they operate solely in the EU market. Now they are forced to verify which of the issued ExNB CS and ExTAG DS are applicable to their equipment.

To further complicate matters, three ExTAG DS published this year - DS 2020/001, DS 2020/002 and DS 2020/004 – contain new interpretations of IEC 60079-0 and IEC 60079-7, which deal with the use of equipment in explosive atmospheres. As these have not yet been transformed into ExNB CS for ATEX, equipment manufacturers going through simultaneous ATEX and IECEx approvals may find themselves in the predicament that for the same requirements different interpretations of test standards may apply.

Lee Ray is operations manager for industrial products UK at TU?V SU?D