What type of respirator provides direct breathing air from an external source, typically used in industrial settings?

A supplied-air respirator (SAR) is specifically designed to provide clean air directly from an external source to the user. This type of respirator is ideal for environments where hazardous air contaminants are present, and the air cannot be effectively cleaned or filtered. SARs are commonly used in industrial settings, where workers may face exposure to toxic gases, vapors, or other harmful substances.

The key feature of an SAR is its connection to a source of breathable air, such as a compressor, which supplies air through hoses that deliver it to the respirator. This ensures that the user has a continuous supply of clean air while they work in potentially dangerous conditions. The design of an SAR allows for a higher degree of protection, as it does not rely on filtering out contaminants but instead provides an external supply of clean air.

In contrast, other types of respirators, like air-purifying respirators (APR), depend on filters to clean the air before it is inhaled, which may not be sufficient in environments with high concentrations of toxic substances. Powered air-purifying respirators (PAPR) also use filters, but they include a battery-powered blower to assist in drawing air through the filters. Open-circuit breathing apparatus generally refers to self-contained breathing