Respirators are often a requirement when welding, cutting, burning, or anytime there is a need to filter particulates due to any process. For instance, paint, lead, dust. They come in several different configurations – full face, cartridge, dust masks, supplied air, and for several different hazards – particulates, organics, etc. If you’re unsure as to which type or under what circumstances you should use a respirator then make sure to read OSHA 1910.134 Respiratory Protection. This the section that governs them and is filled with extensive information about them and their usage.