Home | Business News | Browse by Publication | P | Pharmaceutical Technology Europe

Lost in the ATEX maze? A guide to help you through the intricacies of the ATEX directive, which aims to protect workers in explosive atmospheres.

Article Excerpt
The EU ATEX Directive 1999/92/EC (ATEX 137) regarding the minimum requirements to protect the health and safety of workers potentially at risk from explosive atmospheres came into European law in January 2000. In the UK, the ATEX 137 Directive has been implemented as part of the Dangerous Substances and Explosive Atmospheres Regulations (DSEARs), which were issued in December 2002.

The directive requires that specific risks arising from explosive atmospheres are assessed and that employers classify places where explosive atmospheres may arise and select appropriate work equipment to use in these areas. The directive applies fully to workplaces put into operation for the first time or modified after 30 June 2003. Existing workplaces have until 30 June 2006 to fully comply with the directive. For new workplaces in operation after 30 June 2003, explosion safety must be verified by a person competent in the field of explosion protection with appropriate experience and professional training.

To assess explosion risks, places where explosive atmospheres may arise must first be identified. When such atmospheres occur in sufficient quantities to require special precautions to protect the health and safety of workers, they must be considered as hazardous areas and zoned according to the likelihood and frequency of explosive atmospheres occurring.

When defining hazardous areas it is important to be realistic about zone extents and to avoid unnecessary blanket zoning, particularly when the zones in question are Zones or 20, or Zones 1 or 21, which indicate that explosive atmospheres are present either frequently or occasionally in normal operation (Table 1). Such concentrations (e.g., typically >20000 ppm for gases/vapours or >50 g/[m.sup.3] for dusts) are several orders of magnitude greater than occupational exposure limits permitted under the Control of Substances Hazardous to Health (COSHH) regulations. In the majority of cases, zones in the general workplace should be no worse than Zone 2 or 22.

Categorized equipment

Appropriately categorized equipment should normally be selected for use in areas in accordance with EU ATEX Directive 94/9/EC (ATEX 100), as implemented in the UK by The Equipment and Protective Systems Intended for Use in Explosive Atmospheres Regulations (EPS), unless the risk assessment finds otherwise.

The Heath and Safety Executive (HSE) approved code of practice and guidance...