What are the two general types of respirators?

The correct answer identifies the two general categories of respirators based on their functionality. Air purifying respirators are designed to filter out harmful substances from the air, such as particulate matter, gases, and vapors. These include products like disposable masks and powered air-purifying respirators, which offer varying degrees of protection depending on the type of filter used. On the other hand, supplied air respirators provide clean air from a secondary source, which is essential for environments where contaminants cannot be adequately filtered out. This distinction is critical for understanding the appropriate use of respirators in different hazardous situations.

The focus on functionality and source of air makes this classification particularly relevant for health and safety professionals, as it guides them in selecting the right respiratory protection based on the specific hazards present in a work environment. While other options mention types of masks or categories, they do not capture the broader functional basis for classification, which is fundamental in the context of respiratory protection standards set by organizations like the IICRC.