Air Supply Management

During emergency operations, firefighters perform strenuous and demanding tasks while wearing self-contained breathing apparauts (SCBA). How well firefighters manage the air in their SCBA determines what they can accomplish and how long they remain in operation on the fireground. Furthermore, it is well known within the fire service that the actual duration for work while wearing an SCBA could be considerably less than the nominal value of their SCBA bottle.

After discussions with professional firefighters, training officers, and other commanding officers in the Toronto Fire Services in Ontario, Canada, researchers from the University of Waterloo developed two high-rise scenarios to test how much air firefighters consume during high-rise fireground operations, according to a report from the National Institue of Standards and Technology (NIST).

In the first scenario, the goal was to determine the total number of flights of stairs firefighters could climb while carrying a high-rise pack weighing approximately 40 pounds and consisting of two 1.5-inch hose bundles. When the firefighters had consumed 55 percent of the air in their cylinder, they were stopped and turned around to descend the stairs. The firefighters could continue exiting until their low air alarms sounded. At this point the test was over. If the top (23rd) floor of the scenario was reached,

the firefighters dropped the high-rise pack and descended the stairs to a safe exit. Eight out of 36 firefighters reached the 23rd floor without depleting 55 percentof the cylinder’s air.

In the next scenario, researchers determined how much air firefighters consumed during search and rescue operations. For this test, firefighters climbed five stories carrying the 40-pound high-rise pack. Once they reached the fifth floor, they advanced the hoseline 60 feet and then used a sledge hammer to simulate forcible entry. Firefighters then entered the room, rescued an approximately 165-pound mannequin out of the room and moved the out of the room and moved the mannequin down the stairs to the first floor.

During the simulations, some firefighters were using their air so quickly that their low air alarms were activated as soon as 8 minutes into the scenario. Approximately 50 percent of firefighters’ low air alarms activated within 11-12 minutes when working at a rate they self-selected as their normal level of effort.

This report demonstrates that the physically demanding nature of high-rise firefighting results in the rapid depletion of air during firefighting operations indicates the need for better strategies for air management.

Source: Williams-Bell, F.M., et al., “Air management and physiological responses during simulated firefighting tasks in a high-rise structure,” Applied Ergonomics (2009). Full report:

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