ATEX definitions: Potentially explosive atmospheres are atmospheres likely to become explosive due to local and operational conditions. The ATEX Directive is concerned with explosive atmospheres which are defined as: mixtures with air under atmospheric conditions, of flammable substances in the form of gases, vapours, mists or dusts in which, after ignition has occurred, combustion spreads to the entire unburned mixture.
The following applications are explicitly excluded by the ATEX Directive and must comply with other specific Directives: Medical Devices; equipment or safety devices to be used with explosive or chemically unstable substances; equipment for domestic and non-commercial environments where an explosive atmosphere is generated by leakage of fuel gas; Personal Protective Equipment; offshore vessels; mobile units and means of transport.