Which two types of respirators are commonly recognized?

The correct answer identifies two fundamental categories of respirators: atmosphere-supplying and air-purifying. Atmosphere-supplying respirators provide breathing air directly from a source, such as a compressed air tank, which is essential in environments where the air is unsafe or unbreathable due to a lack of oxygen or presence of harmful substances. These respirators are vital in situations such as firefighting or gas leak interventions, where the ambient air quality is compromised.

On the other hand, air-purifying respirators are designed to filter out contaminants from the air as the user breathes. This category includes devices with filters, cartridges, or canisters that remove specific airborne hazards, such as particulates or toxic gases, allowing the user to breathe in clean air. Understanding these two types of respirators equips individuals with the knowledge to select the appropriate breathing protection based on the specific hazards they may encounter.