BS EN 12942. Respiratory protective devices. Power filtering devices incorporating full face masks, half masks or quarter masks. Requirements, testing, marking|Electrical components, Filters, Marking, Performance testing, Air filters, Flexible pipes, Carbon dioxide, Designations, Air, Visors, Flow measurement, Supplied air breathing apparatus, Accident prevention, Joints, Weight (mass), Strength of materials, Fire tests, Determination of content, Flow rates, Inspection, Classification systems, Breathing apparatus, Respirators, Grades (quality), Specimen preparation, Flammability, Leak tests, Volume, Safety devices, Masks (protective clothing), Test equipment, Noise (environmental), Testing conditions, Acoustic measurement, Instructions for use, Performance