What type of respirator provides clean air from a source outside the contaminated area?

A supplied-air respirator is specifically designed to provide clean air from an uncontaminated source, typically through a hose connected to a compressed air tank or a distant, clean air supply. This type of respirator is essential in environments where the air is harmful to breathe, ensuring that the user has a reliable source of breathable air. It is particularly useful in situations where exposure to high levels of harmful substances is possible, as it completely separates the user from the contaminated atmosphere.

In contrast, an air-purifying respirator relies on filters or cartridges to remove contaminants from the air before it is inhaled. Non-powered particulate respirators (often disposable) filter out particles but do not provide a clean air supply. Likewise, a chemical cartridge respirator uses specific cartridges to filter out harmful gases but does not supply fresh air from an external source. Thus, the supplied-air respirator is the most appropriate option for ensuring an uninterrupted supply of clean air from a safe environment.