'To many firefighters, ‘air management’ still means waiting for the low-air vibration alert or alarm to sound, signaling it’s time to leave the building. This occurs when three-fourths of the air supply has been consumed. Many consider that such a procedure is acceptable during a routine room-and-contents fire in a small building. However, take a look at how many firefighters have ‘run out of air’ in residential fires and lost their lives! In larger structures, or where there are large numbers of firefighters operating, the issue of interior accountability and ‘air management’ is critical. Where SCBA operations are extended to periods longer than thirty minutes and relief crews are required, a greater element of SCBA control is called for.
During the tragic Charleston SC Sofa Superstore furniture warehouse fire in 2007 where nine firefighters lost their lives as the fire suddenly escalated, a firefighter recounted how several firefighters came running past him in the blinding smoke screaming their cylinder air supplies had almost run out and that they were unable to find the exit. He tried to calm them but they were in a state of panic as all of their low-air alarms were actuating. The firefighter knew the way out and escaped, but tragically all the others died as their cylinders emptied, one by one.
As a rule of thumb, firefighters undertaking hose-lays up a stairway and completing a search pattern in a training situation, will reduce the air supply of 30-minute cylinders to around 20 minutes (to empty) and 45-minutes cylinders will be reduced to about 30 minutes (empty). Now by using up 75% of cylinder contents, leaving a 25% time to allow exit, means that 30-minute cylinders may only allow five or six minutes to exit and 45-minute cylinders will allow seven or eight minutes (air reserve to empty).
The 2007 version of NFPA 1404 covers this area of firefighter safety –
· 1. Exit before you use your reserve air
· 2. The alarm indicates use of reserve air
· 3. Alarm activation is an ‘immediate’ action item