Definition – What does Self-Contained Breathing Apparatus (SCBA) mean?
A self-contained breathing apparatus (SCBA) is a respiratory device that contains and delivers breathable compressed air. It is typically used by the firefighters and rescue workers while operating in areas of immediate danger to life and health, such as inside a building inferno or in a mine filled with smoke or toxic gas.
A self-contained breathing apparatus may also be called a compressed air breathing apparatus (CABA).
HSSE WORLD explains Self-Contained Breathing Apparatus (SCBA)
An SCBA consist of the following:
- A single or a pair of high-pressure tanks made of steel, aluminium or carbon-fibre composite (2,216 to 4,500 psi or 150-310 bars)
- One pressure regulator
- A face-seal mask or facepiece, mouthpiece and connecting supply pipes
- A carrying frame or pack
SCBAs are found in two different categories:
- The closed-circuit type filters, supplements and recirculates exhaled gas. Where a longer-duration supply of breathing gas is needed, such as in a mine, closed-circuit SCBA sets are used.
- Open-circuit sets are filled with breathable compressed air that lasts for 30-60 minutes. The air is stored in the tanks and the pressure is regulated to the same level of the breathable atmosphere by a regulator. Newly invented carbon fiber composite cylinders provide breathable air for about 90 minutes in a single fill. These cylinders weigh about 15 – 18 kg. The user uses a face-sealed mask where a positive pressure is maintained to ensure that no outside air can come into the breathing system