What type of air does open-circuit SCBA use?

Open-circuit self-contained breathing apparatus (SCBA) systems use compressed air as their primary breathing medium. This type of SCBA delivers air that is drawn from a high-pressure cylinder, allowing the user to breathe freely in hazardous environments where the surrounding air may not be safe or sufficient for breathing. The compressed air is typically filtered to remove contaminants before being stored in the cylinder, but the air itself is not pure oxygen or nitrogen, both of which have different applications and risks associated with their use. Open-circuit SCBA is widely used in firefighting and other emergency services because it provides a reliable supply of breathable air for extended periods, even in smoke-filled or oxygen-deficient environments. This design allows firefighters to perform their duties effectively while minimizing the risks to their health and safety.