Sulphur hexafluoride (SF6), Nitrogen (N2) and Carbon Tetrafluoride (CF4), are gases commonly used for electrical equipment. Taking into account environmental concerns, particular attention shall be paid to re-use criteria for SF6 and its mixtures with N2 and CF4 as used in electrical equipment. This International Standard provides criteria for re-use of SF6 and its mixtures after recovery and reclaiming from electrical equipment (e.g. for maintenance, at the end-of-life). Procedures for recovering and reclaiming used SF6 and its mixtures are out of the scope of this Standard and are described in IEC 62271-4. Description of the different methods of analysis, by-products, procedure for evaluating the potential health effects from by-products, cryogenic reclaiming of SF6, and reclaiming recommendations are provided in the annexes of this standard. Storage, transportation and disposal of SF6 and its mixtures are out of the scope of this Standard and are covered by IEC 62271-4. Procedures to determine SF6 leakages are described in IEC 60068-2-17. For the purposes of this document, the complementary gases used in SF6 mixtures will be limited to N2 or CF4.