Avoid the Flames
New tests have shown how important it is for firefighters to deploy fire shelters where flames will not contact the shelters. If flame contacts the fire shelter, the shelter can release gases that ignite and burn inside the shelter. In the event of a burnover, the fire shelter is still one of the firefighter’s most valuable pieces of personal protective equipment. The shelter must be deployed where it will not be contacted by flame if it is to provide the most benefit.
Can the fire shelter still provide effective protection in the case of a burnover? Yes. The fire shelter provides effective protection within its design limitations. In the past 20 years, the fire shelter has saved hundreds of lives and prevented many serious burn injuries. The shelter reflects about 95 percent of the radiant heat that reaches it. Because so little heat is absorbed, the temperature of the shelter material and of the air inside the shelter rises slowly. The shelter does not offer effective protection against direct flame or "convective" heat.This type of heat is absorbed quickly by the shelter material, causing temperatures to rise rapidly.
For years, fire shelter training has stressed the importance of deploying shelters where flames will not contact the shelter. This has not changed. We now know that when the glue bonding the layers of the fire shelter reaches about 475ºF the glue starts to break down. The shelter begins to fill with flammable smoke and gases. As the temperature rises, these gases are released more rapidly. If flames enter the shelter, these gases can ignite and burn (Figure 1).
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Figure 1: When direct flame contacts the fire shelter, glue in the shelter material can form gases that can ignite inside the shelter |