What is ATEX certification?
ATEX stands for atmosphères explosible. It’s a European Union directive from the European Committee for Standardization that covers “equipment and protective systems intended for use in potentially explosive atmospheres.” An atmosphere can be explosive for several reasons, including flammable gases, mists or vapours, or combustible dust.
All equipment and protective systems intended for this type of use in the EU must meet ATEX health and safety requirements. In this way, the directive is similar to an OSHA or NEC standard in the United States.
Equipment manufacturers whose products are intended to be used in Europe are responsible for making sure their equipment complies with ATEX standards. This process involves conformity assessment procedures and certification by a third party called a “Notified Body.” Certified equipment is marked with the symbol shown in graphic.
Zone classification explained
Atex Zone 0 – A place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapour or mist is present continuously or for long periods or frequently.
Atex Zone 1 – A place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapour or mist is likely to occur in normal operation occasionally.
Atex Zone 2 – A place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapour or mist is not likely to occur in normal operation but, if it does occur, will persist for a short period only.
The aim of directive 94/9/EC is to allow the free trade of ‘ATEX’ equipment and protective systems within the EU by removing the need for separate testing and documentation for each member state.
The regulations apply to all equipment intended for use in explosive atmospheres, whether electrical or mechanical, including protective systems. There are two categories of equipment 'I' for mining and 'II' for surface industries. Manufacturers who apply its provisions and affix the CE marking and the Ex marking are able to sell their equipment anywhere within the European union without any further requirements with respect to the risks covered being applied. The directive covers a large range of equipment, potentially including equipment used on fixed offshore platforms, in petrochemical plants, mines, flour mills and other areas where a potentially explosive atmosphere may be present.
In very broad terms, there are three preconditions for the directive to apply: the equipment a) must have its own effective source of ignition; b) be intended for use in a potentially explosive atmosphere (air mixtures); and c) be under normal atmospheric conditions.
The directive also covers components essential for the safe use and safety devices directly contributing to the safe use of the equipment in scope. These latter devices may be outside the potentially explosive environment.