When the low air alarm sounds, how many minutes of air are typically left on a 45-minute bottle?

When the low air alarm sounds on a 45-minute bottle of SCBA, it is designed to provide a safety warning that allows the user to have a remaining air supply of approximately 15 minutes. This time serves as a critical alert for the user to exit a hazardous environment or to perform necessary safety procedures before the air supply runs out.

The low air alarm is specifically calibrated to activate when the air pressure in the bottle reaches a point where approximately 25% of the total air supply remains. This means that, for a 45-minute cylinder, the user can typically expect about 15 minutes of operational time left, ensuring that they have enough air to exit safely or address any urgent needs.