What are the two general types of self-contained breathing apparatus (SCBA)?

Self-contained breathing apparatus (SCBA) are vital safety equipment used by firefighters and other emergency responders to provide breathable air in hazardous environments. The two general types of SCBA are distinguished by their air supply systems: open circuit and closed circuit.

Open circuit SCBA systems release exhaled air into the environment. In these systems, the user inhales clean, pressurized air from a tank, and after breathing, the air is expelled, releasing it back into the atmosphere. This type is commonly used in firefighting due to its simplicity and ease of use, providing a continuous supply of fresh air as needed.

Closed circuit SCBA, on the other hand, recirculates exhaled air. In this system, the air is filtered and purified, allowing the user to breathe the same air multiple times by removing carbon dioxide and adding oxygen. Such devices are more compact and can be beneficial in situations where air supply is limited or in longer-duration tasks.

Understanding the differences between these types helps responders select the appropriate equipment based on the specific needs of the environment they are operating in, ensuring they have the necessary level of safety and operational capability.