This International Standard defines the quality requirements and properties for technical grade sulfur hexafluoride (SF6) for use in electrical equipment. It covers the properties and methods of test applicable to SF6 when this substance is supplied for use in connection with any electrical equipment. This second edition differs widely from the first one. The focus is now on the specification of the gas needed for electrical applications. As a consequence, the term employed to name this gas is "technical grade" in place of "new". Based on experience, the acceptable impurity levels have been increased. However, the gas as defined in this new second edition has the same performance in electrical equipment as the gas previously defined in the first edition. The analytical methods for the SF6 analysis have been removed as it has been found confusing to prescribe methods that can become obsolete very rapidly.