According to the British Government, explosive atmospheres can be caused by flammable gases, mists or vapours or by combustible dusts. If there is enough of the substance, mixed with air, then all it needs is a source of ignition to cause an explosion. ATEX is the name commonly given to the two European Directives for controlling explosive atmospheres: 1) Directive 99/92/EC (also known as ‘ATEX 137’ or the ‘ATEX Workplace Directive’) and 2) Directive 94/9/EC (also known as ‘ATEX 95’ or ‘the ATEX Equipment Directive’).