The term ATEX is used for the European Union's (EU) 94/9/EC directive addressing tools and instrumentation intended for use in potentially explosive environments. The directive was purposed to support trade within the EU through alignment of laws governing the member states and went into effect on July 1, 2003. ATEX covers a broad array of safety tools and instrumentation - including gas detectors.
The first ATEX directive (94/9/EC) addresses needs of tools used in areas where there is a risk of explosion. Manufacturers must fulfill the directive necessities in their instrument design and mark the products with the relevant support. The second ATEX directive (99/92/EC) addresses the minimum health and safety necessities that users must fulfill when working within areas containing a danger of explosion.