Dust mask is one piece in a pack wear the masks at all times when in a contaminated area.do not remove. After leaving the contaminated area leave the mask and discard. In thr event any breathing diffculty occurs due to colging,replace mask with a new one.use ths mask according to tge required occupational health and safety acts and procedures tgis product is designed to be used once only.once removed from the face it should be discarded.Place the mask over your mouth. Tge seal of the respirator must be checked before entering the work area.