This European Standard specifies minimum requirements for powered filtering devices incorporating ahelmet or a hood with gas, particle or combined filter(s) for respiratory protection. It does not cover devicesdesigned for use in circumstances whereThere is or might be an oxygen deficiency (oxygen less than 17 %by volume). Also, it does not cover respiratory protective devices designed for escape purposes.Laboratory and practical performance tests are included forThe assessment of compliance withTherequirements.