The legislation applying to the safe handling of potentially explosive atmospheres (ATEX) has led to some confusion and mixed messages. There is no doubt that when working with wood and associated materials you are working with “dangerous substances and explosive atmospheres” as defined by the statutory Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR).

DSEAR are the UK regulations that implement the European Directive 99/92/EC, often known as the “ATEX users’ directive”. They do not directly control the manufacture of the production equipment, but nonetheless put the onus fairly and squarely on the employer or operator to be safe and to comply. This directive contains some definite requirements such as:

  • If the workplace was already in use before July 2003, then it must meet requirements by July 2006.

  • If the workplace was already in use before July 2003, but modified before July 2006 it must meet requirements from the date of the modification.

  • If the workplace was in use for the first time after July 1, 2003 it must meet the requirements from starting date.

  • It is the employer’s responsibility to inform his supplier of the hazardous zone classification, if any, where the supplier’s equipment will be situated.

The employer must make sure all production equipment that may handle wood and associated dust and waste is safe and legal. This may be difficult to determine with older equipment, where any future defence will depend upon the quality of the risk assessment. In the event of an accident, this may be tested in court.

All manufacturers and suppliers of dust and waste handling equipment for use with potentially explosive atmospheres have a legal duty to ensure that it complies with the directive 94/9/EC, known as the ATEX “manufacturers’ directive”. Items regarded as “protective equipment” such as explosion relief panels and dust or waste discharge devices must be externally certified by a recognised Notified Body. The manufacturer must maintain a Design and Manufacturing Quality Assurance System that has been externally certified and audited in accordance with the European Standard EN 13980.

Whilst costly and time consuming for the manufacturer, it is a requirement for manufacture of these items and it ensures consistent quality and safety. It

is an investment that is required by law. So purchasers of such equipment should ensure that their suppliers are suitably qualified.

Within the timber trades sector, the focus of ATEX compliance will be largely on waste and dust removal and handling systems. Dust collectors, extraction fans and waste transport systems must be considered within the general risk assessment. Although not all standards are harmonised, certain principles are fixed affecting the design of components installed since July 1, 2003.

  • If explosion ventilation is fitted to a vessel, such as a dust filter/collector, then the vent device type must have been externally tested and certified by a Notified Body and it will have a serial plate listing information including the certificate number and origin.

  • The strength of the vessel must be known in order to size correctly the explosion relief panel. Normally this information will be derived from an independent explosion test programme.

  • Any discharge device is regarded as a protective device under ATEX standards and must be similarly tested and certified externally.

  • Fans carrying dusty air must be protected against the possibility of causing unwanted sources of ignition. Again, the design of these must have been externally examined and certified by a Notified Body.

  • Explosion relief devices should ventilate only into a safe area.

  • Dust extraction equipment for wood dusts are subject to the provisions of ATEX wherever it is located, even if it is outdoors.

DISA, together with some other manufacturers have invested heavily in order to comply with this directive and makes and supplies only properly certified protective systems and enclosures with proven strength.

Employers and purchasers should beware those companies who don’t. They may offer a cheaper installation. The HSE inspector may not spot deficiencies immediately. But the installation will be less safe and a subsequent claim for losses could be disputed by the insurer. And the employer will become liable under the law. They will get no comfort from HSE either. We are all required to know and obey the law.