... mask against C6H6,CL2 SO2 1.Purpose and CharacteristicMF25 filter half mask is applied to the workers, who work in the ... of mask, the cartridge, Inhale and exhale valves, rubber headbands.2. Technical Standards2.1 Cartridge (1#) life time ≥ 20 min; Cartridge ... something leaky or broken, it should be forbiddened to use3.2 During the using, when the cartridge loses efficacy, and the ...