Closed-circuit SCBA uses what type of air?

Closed-circuit SCBA (Self-Contained Breathing Apparatus) is designed to be a more efficient system for breathing in environments where fresh air supply is limited or hazardous. In a closed-circuit setup, the device uses a supply of compressed oxygen that is stored in tanks.

This system is distinct from other types of breathing apparatus because it recycles the air that the user exhales. When a person exhales, the carbon dioxide is removed, and the remaining oxygen is recirculated for reuse. This rebreathing process allows for an extended duration of breathable air in comparison to open-circuit systems, which vent exhaled air into the atmosphere.

Using compressed oxygen as opposed to plain atmospheric air allows firefighters to operate in extremely toxic or oxygen-deficient environments without compromising their safety or effectiveness. The design of closed-circuit SCBA systems emphasizes both sustainability and safety, recirculating the oxygen while removing carbon dioxide, thereby enhancing performance during prolonged tasks in hazardous conditions.