Applies to industrial safety helmets for protection of the wearer's head in building and construction, underground working, quarrying, shipbuilding, and occupations with similar hazards. It deals with the construction and materials of the helmet shell and head harness, mechanical strength of the shell, and finish of the helmet. Appendices set out test requirements for electrical insulation resistance, stiffness, shock absorption by direct measurement and by use of an aluminium bar, penetration and flammability of materials. Additional optional protection may be required by particular industries and these may be specially called for.