It might surprise you to learn that an estimated five million U.S. workers are required to wear respirators in 1.3 million workplaces. A respirator is a device that protects you from inhaling dangerous substances. Different types of respirators offer protection from different hazards. Respirators either filter particles from the air, chemically clean the air, or supply clean air from an outside source. As you might've guessed, exposure to these hazards can cause all sorts of health issues, from asthma to cancer. There are a couple of different types you may encounter, so in this course, we'll talk through those. We'll also go over some cautions, limitations, and restrictions when it comes to respirators. Lastly, we'll touch on some work practice control measures for handling airborne hazards.