The Directive ATEX 94/9/EC of 23rd March 1994 on the approximation of the Laws of the Member States concerning equipment and protective systems intended for use in potentially explosive atmospheres has been published on the official EC Gazette No.100 of 19th April 1994.
“Equipment” is defined as any item, which contains or constitutes a potential ignition source.
“Protective systems” means units which are intended to halt incipient explosions immediately and/or to limit the effective range of explosion flames and pressures. They may be integrated into equipment or separately placed for use as independent systems. Gas detectors, whether fixed or portable, are considered typical protective systems (safety devices).
The Directive was introduced on a transitional period in March 1996, and will become mandatory from the 1st July 2003. During the interim period, standards currently in force concerning electrical equipment for use in potentially explosive atmospheres remain valid, i.e. the framework Directive 76/117/EEC (Group II- surface devices) and the Directive 82/130/EEC (Group I-mines susceptible to firedamp).
There are a few important novelties in the Directive 94/9/EC which are worth mentioning for both manufacturers and users of equipment and protective systems intended for use in potentially explosive atmospheres:
- The Directive also applies to safety or control devices installed outside the hazardous area but having an explosion protection function (for example, Control Units installed in a safe area and connected to remote EX gas detectors installed in a potentially explosive area)
- All risks of explosion are considered (i.e. mechanical shock, overheating, acoustic and optical emissions, EM emissions) affecting both electrical and non-electrical equipment for use in potentially explosive atmospheres
- The Directive follows the guidelines “new approach” of the European Council, addressing general requirements i.e. “essential health and safety requirements ” relating to the design and construction of equipment for use in potentially explosive atmospheres (Annex II)
- Based on the “new approach” concept, these essential safety requirements (ESR) address the basic criteria to assess the conformity of the equipment, even if there is a lack of specific harmonised Norms, helping progress in the design and use of innovative products
- The Directive includes equipment for installation in both surface (Group II) and mines (Group I) environments, considering that explosion risk, protection means and testing methods are very common to both typologies, though the classification remains different
- Criteria are set to classify the devices by categories in function of the protection level and the zone of use. Different procedures on how to assess conformity are set in function of product and its category. For example, electrical devices of category 1 and 2 are subjected to certification of the prototype by a Notified Body (EC-Type Certification- Annex III) as well as to production surveillance by the Notified Body (see also previous article – Ed)
- The equipment and protection devices conformable to the Directive are to be marked by the symbol of explosion protection (epsilon-X in a hexagon) as well as display a CE mark proving their conformity to the previously applicable Directives. Safety devices with a measuring function (like gas detectors) must meet a recognised performance standard, i.e. EN 50054, 50057 (EN 61779-IEC 1779) and EN 50271 for flammable gas detectors, within the scope of the ESR (Annex II 1.5.5 – 1.5.6
- Safety devices must function independently of any measurement or control devices required for operation (ESR Annex II 1.5.1)
The following are excluded from the scope of the Directive:
Medical devices
Explosive and unstable chemical substances
Equipment intended for use in domestic environments
Personal protective equipment covered by Directive 89/686/EEC
Vessels and offshore units
Means of transport
The ATEX Directive 99/92/EC, introduced on 16th December 1999 concerns the minimum requirements for improving the safety and health protection of workers potentially at risk from explosive atmospheres
It requires employers to:
- Prevent and provide protection against the explosions
- Carry out, document and keep up to date an explosion risk assessment (Directive 89/391/EEC)
- Ensure a safe working environment and appropriate supervision of workers in hazardous areas
- Classify hazardous areas into zones and provide warning signs in a specified form (Directives 92/58/EEC and ATEX 94/9/EEC)
- Satisfy the requirements of Annex II of the Directive which applies to places classified as hazardous areas and also equipment installed in non-hazardous areas but required for safe operation of equipment installed in hazardous areas, among the most important being:
- Training of Workers
- Only bringing into service equipment which can be safely used in an explosive atmosphere
- Selecting equipment and protective systems on the basis of the categories set out in ATEX 94/9/EC (Annex II Section B of Directive 99/92/EEC)
- Minimising the risk of an explosion through the proper design, construction, assembly, installation and maintenance of plant equipment
Workplaces used for the first time after June 30th 2003 must comply with the Directive immediately. Existing workplaces must comply with the Directive no later than 30th June 2006.
Important changes made to existing workplaces after 30th June 2003 must comply with the Directive.
The introduction of these two ATEX standards should finally harmonise standards throughout the EU for the benefit of both manufacturers and users by improving reliability and reducing the risk of explosions in the workplace.
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Published: 10th Apr 2003 in Health and Safety International