If air supply is partially or completely cut off during use, what is the first action?

If air supply is partially or completely cut off during use, what is the first action?

• A. Fully open purge valve
• B. Check that cylinder is fully opened
• C. Leave contaminated area immediately
• D. Return to work

Answer: (A)

When air supply is compromised, the immediate goal is to restore a safe breathing path from the cylinder and clear any stale or contaminated air in the regulator/line. Fully opening the purge valve accomplishes this quickly by flushing the regulator and line, which helps confirm whether fresh air from the cylinder can reach the facepiece. It’s the fastest way to clear the path and verify airflow before diagnosing other causes. If air still isn’t flowing after purging, you would then check the cylinder valve and system connections, but purging comes first because it directly tests and clears the immediate breathing path. Leaving the contaminated area or returning to work aren’t appropriate first actions when the air supply is cut off, though leaving the area is a separate safety step if breathing cannot be restored.

When air supply is compromised, the immediate goal is to restore a safe breathing path from the cylinder and clear any stale or contaminated air in the regulator/line. Fully opening the purge valve accomplishes this quickly by flushing the regulator and line, which helps confirm whether fresh air from the cylinder can reach the facepiece. It’s the fastest way to clear the path and verify airflow before diagnosing other causes.

If air still isn’t flowing after purging, you would then check the cylinder valve and system connections, but purging comes first because it directly tests and clears the immediate breathing path. Leaving the contaminated area or returning to work aren’t appropriate first actions when the air supply is cut off, though leaving the area is a separate safety step if breathing cannot be restored.