When experiencing a loss of demand air supply, what is the first step you should take?

When experiencing a loss of demand air supply, the first step to take is to check the valve to ensure it is open. Confirming that the valve is open is crucial because it directly affects the flow of air to the user. If the valve is closed or partially obstructed, it would prevent air from reaching the facepiece, leading to a loss of air supply.

By verifying the valve’s status first, you can quickly determine if the issue can be rectified without further action. This step is essential in maintaining air supply before considering other options, such as calling for help or adjusting the facepiece, which may not resolve the underlying air supply problem. Properly addressing the valve position allows for a timely response to the situation and can significantly enhance safety and effectiveness in an emergency.