Specifies minimum performance criteria and test requirements for protective headgear for vehicle users, designed to mitigate the adverse effects of a blow to the head. The primary intended use is by motor cyclists, but it is equally applicable to all vehicle users, including racing car drivers and racing motor cyclists under Australian conditions. Tests for impact attenuation, penetration resistance, strength of retention system and its attachments, and peripheral vision are prescribed by reference to AS 2512. Specific marking requirements are detailed.