These are not really protective devices: they perform badly and should not be used for protection against fine dusts, welding fumes, asbestos, fine sand, paint spray, gases, vapours or aerosols, and other hazardous substances.
This advice has come from the Health and Safety Executive (the equivalent of the WorkCover Authority), which wants the masks withdrawn from sale in the UK. The warning is in support of the Health and Safety Commission's (HSC) campaign to reduce respiratory diseases such as occupational asthma, which is the most frequently diagnosed occupational related respiratory disease in Great Britain. British unions have supported the HSE in this initiative.
Last amended January 2003.