1.1This European Standard specifies the constructional requirements for fans constructed to Group II G (of explosion groups IIA, IIB and hydrogen) categories 1, 2 and 3, and Group II D categories 2 and 3, intended for use in explosive atmospheres.NOTE 1Operation conditions for the different categories of fans used in this European Standard are defined in Clause 4.NOTE 2Technical requirements for category 1 D fans are not given in this document. Where explosive dust atmospheres are regularly conveyed, explosion protection measures as described in EN 1127–1 are required if this specific us is needed.1.2This European Standard does not apply to group I fans (fans for mining), cooling fans or impellers on rotating electrical machines, cooling fans or impellers on internal combustion engines.NOTE 1Requirements for group I fans are given in EN 1710.NOTE 2The requirements for electrical parts are covered by references to electrical equipment standards.1.3This European Standard specifies requirements for design, construction, testing and marking of complete fan units intended for use in potentially explosive atmospheres in air containing gas, vapour, mist and/or dusts. Such atmospheres may exist inside (the conveyed atmosphere (flammable or not)), outside, or inside and outside of the fan.1.4This European Standard is applicable to fans working in ambient atmospheres and with normal atmospheric conditions at the inlet, having-absolute pressures ranging from 0,8 bar to 1,1 bar,-and temperatures ranging from −20 °C to +60 °C,-and maximum volume fraction of 21 % oxygen content,-and an aerodynamic energy increase of less than 25 kJ/kg.NOTE 125 kJ/kg is equivalent to 30 kPa at inlet density of 1,2 kg/m3.This European Standard may also be helpful for the design, construction, testing and marking of fans intended for use in atmospheres outside the validity range stated above or in cases where other material pairings need to be used. In this case, the ignition risk assessment, ignition protection provided, additional testing (if necessary), manufacturer's marking, technical documentation and instructions to the user, should clearly demonstrate and indicate the equipment's suitability for the conditions the fan may encounter.This European Standard should not apply to integral fans as a part of Diesel engines, vehicles or electric motors.NOTE 2Where undated references are used in the body of the standard the latest edition applies.