Why is it Important to Recognize Flashover in a Room Fire?
by John D. DeHaan California Institute of Criminalistics In the growth of a compartment (room) fire, flashover is defined as the transition between the fire growing by igniting one item and then another (by direct flame contact, radiant heat, convective heating, or immersion in the got gas layer) to the point where all fuel packages in the compartment are on fire (full involvement) and are burning as fast as air (oxygen) can be made available through window and door openings. This transition may occur throughout a room in just a few seconds in a small, heavily fueled room, over a period of minutes in large rooms, or may never take place due to insufficient size (heat release rate) of the fire. Because it is a transition, defining the “exact moment” is often a problem. It can be likened to defining the moment when one has crossed a bridge: is it when one sets foot on the bridge, one gets halfway, or sets foot on the other side? It is all part of the process, and the time it takes for co
