The SCBA air supply is stored in the air cylinder.

The SCBA air supply is stored in the air cylinder.

• A. The air cylinder contains air for the user to breathe
• B. The air cylinder stores water
• C. The air cylinder is only for ballast
• D. The air cylinder is optional

Answer: (A)

In a self-contained breathing apparatus, the air supply is stored in the air cylinder, which is filled with breathable air at high pressure. This design makes the wearer self-sufficient in hazardous or oxygen-deficient environments because the regulator steps the pressure down and delivers breathable air to the facepiece as needed. The cylinder’s purpose is strictly to provide air for breathing, not water or ballast, and it isn’t optional—without that air supply, the equipment cannot protect you.

In a self-contained breathing apparatus, the air supply is stored in the air cylinder, which is filled with breathable air at high pressure. This design makes the wearer self-sufficient in hazardous or oxygen-deficient environments because the regulator steps the pressure down and delivers breathable air to the facepiece as needed. The cylinder’s purpose is strictly to provide air for breathing, not water or ballast, and it isn’t optional—without that air supply, the equipment cannot protect you.