Many industrial sectors work with gases, vapours, fumes and dusts; in other areas these flammable substances develop during processing. Explosion hazard is reached when air meets an ignition source. In order to prevent such dangers and all the resulting damages to the environment, persons and equipment, explosion protection measures were developed. Within the EU, the field of explosion protection is harmonized and regulated through the framework directive 94/9/EC, the so-called ATEX directive, which was passed in 1994.