Flashover and backdraft have been confused for years. Part of the reason for the confusion is that they produce a very similar result—a large fire that envelops the whole room or area. They are, however, very different in how and why they occur. Misconceptions have also evolved around these phenomena. Among these erroneous beliefs are that a flashover will occur within four minutes of first flame and that a backdraft will occur only in tightly sealed buildings. Both are dangerous misconceptions. There is NO time frame for flashover, and a backdraft can occur in almost any enclosed space given the proper conditions.
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