At what psi does the low air alarm operate?

The low air alarm operates at a threshold designed to alert firefighters when the air pressure in the breathing apparatus is nearing a critically low level. Typically, this threshold is established between 55 and 75 psi, which ensures that personnel are given sufficient warning to exit hazardous environments before the air supply becomes insufficient for safe breathing. This range effectively balances safety and operational readiness, allowing sufficient pressure for breathing while signaling the need to exit or recharge the air supply.

Establishing the alarm at a pressure lower than 55 psi could pose risks since it may not allow enough time for safe evacuation, while setting it too high may lead to situations where firefighters could run out of air without an adequate warning. Thus, the answer indicating the low air alarm operates at a pressure of 55-75 psi aligns with established safety protocols and practices in firefighting.