What is a protective breathing equipment?

Protective breathing equipment is equipment (often a face mask or a full suite) connected to a set of filters that filter the air from impurities that exist in certain ubnormal circumstances. One example is. People that spray cars need such equipment because as much as 60% of the output of a spray gun (pigment, hardener and tinner) goes in the air and only 40% on the car. This is extremely toxic and so you need protective breathing equipment. Simialry, firemen that could need to go inside buildings that are full of fire fumes. They would need such equipment too. Needless to say, such equipment would need to filter out fire toxic fumes.