Teaching engineers about ATEX

Rather than just passing exams, you must be able to apply safety knowledge on a sustained basis, writes Ron Sinclair of BASEEFA:

ATEX means different things to different people. It is an acronym from the French “Atmosphere Explosible”, and can refer to two different European Union directives, depending on context - the fourth and fifth ATEX Directives; the first three were repealed in 2003.

Directive 94/9/EC has been compulsory since July 2003, and is a “trading directive”. It only concerns safety insofar as to set requirements that will prevent concern on safety becoming a barrier to trade within the European Economic Area.

Those who place explosion protected (Ex) equipment on the European market must be able to show compliance with the directive. Every item of equipment must be accompanied by the manufacturer’s Declaration of Conformity (DoC), backed up by conformity assessment evidence, which varies in thoroughness according to the ’category’ of the equipment.

Category 1 equipment has the highest level of protection against being a source of ignition and requires the highest level of proof of conformity, through Category 2 (medium) to Category 3, which has the lowest level of protection and the lowest level of proof of conformity.

Directive 1999/92/EC - also known as ’ATEX 137’ or the ’ATEX Workplace Directive’ - applies directly to hazardous area installations and became mandatory in two stages.

From July 2003, all hazardous areas had to be classified in “Zones”. Zone 0 indicates the possibility that an explosive gas or vapour mixture may be present continuously or for long periods. In Zone 1, the atmosphere is likely to exist, but not for long periods, and in Zone 2 the atmosphere is most unlikely to exist. For dust atmospheres - particularly relevant in the food and pharmaceutical industries - the equivalent terms Zone 20, Zone 21 and Zone 22 are used.

In the UK, most major sites had been classified this way for many years, but there were many smaller sites where classification had not been completed. The classification relates only to the probability that an explosive gas, vapour or dust atmosphere may be present, but requires a proper assessment of the processes being undertaken in a particular plant.

The second mandatory stage required that a full ignition risk assessment had been made, for all existing plant, by July 2006. From the number of enquiries still received over three years later, Baseefa is aware that some companies are still struggling to get to grips with this part of the directive.

Existing equipment
For existing electrical equipment the process has not usually been too hard, as there are likely to be certificates for all equipment less than 30 years old. However, standards for non-electrical equipment (process vessels, conveyers, etc) were only drafted earlier this decade, so the evidence is much less clear.

In the UK, the ATEX “installations” Directive has been implemented in the Dangerous Substances and Explosive Atmospheres Regulations (DSEAR), along with part of the Chemical Agents Directive (CAD), the remainder of CAD being implemented in the CoSHH Regulations.

The two directives work together, and notified bodies, such as Baseefa, have a vital role to play in assessing equipment, both as a mandatory service for Category 1 equipment and some Category 2 equipment, and as a voluntary service for the remaining Category 2 equipment and Category 3 equipment. Most will also offer advice and training to plant owners struggling with their DSEAR risk assessments.

However, the directives only provide a framework. Safety is down to the actions of real people in real situations. One of the prime concerns is the level of competence of those involved in the installation, commissioning, inspection, maintenance and repair of the plant and its equipment.

For a number of years, the CompEx Scheme has been responsible for providing training and examination of people working in this area. The training is both practical and theoretical, and there are a number of service providers in the UK and some elsewhere in the world.

But competence is more than just receiving training and the ability to pass examinations; it is the sustained ability to apply that knowledge in the work environment.

New development

The IECEx Scheme for Certification of Personnel Competency was launched in 2009 and Baseefa is among the first certification bodies undergoing assessment for the ability to deliver the service.

The IECEx scheme, which is expected to be working on a practical level early in 2010, is part of the philosophy of looking after equipment from manufacture (the IECEx Product Certification Scheme), through installation, inspection and maintenance, to repair (the IECEx Service Facility Certification Scheme).

In all aspects, the IECEx schemes are more thorough than the equivalent requirements of ATEX. For manufacturing, the scheme offers proper product certification at all levels and the certification bodies accepted into the scheme have passed a far more rigorous assessment than that required to become a notified body for ATEX.

The top-level document is the IECEx Certificate of Conformity, which can be viewed directly on the IECEx web site. In contrast, for ATEX, the top level document is the manufacturer’s own Declaration of Conformity, which may or may not have third-party certification backing it up.

Those who place explosion protected (Ex) equipment on the European market must be able to show compliance with the directive For a number of years, the CompEx Scheme has been responsible for providing training and examination of people working in this area.

Ron Sinclair is managing director of BASEEFA - a certification body for electrical and mechanical equipment installed and used in potentially explosive atmospheres