This 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 Operation conditions for the different categories of fans used in this European Standard are defined in Clause 4. This 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 1 Requirements for group I fans are given in EN 1710. NOTE 2 The requirements for electrical parts are covered by references to electrical equipment standards. This 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 fluid), outside, or inside and outside of the fan. This European Standard is applicable to fans working in the range of ambient atmospheres having absolute pressures ranging from 0,8 bar to 1,1 bar, temperatures ranging from - 20 °C to + 60 °C, maximum volume fraction of 21 % oxygen content and an aerodynamic energy increase of less than 25 kJ/kg. NOTE 1 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. NOTE 2 This European Standard does not apply to integral fans of electric motors. NOTE 3 Where undated references are used in the body of the standard the latest edition applies.