During which stage of a fire is the risk of flashover at its peak?

The growth stage of a fire is when the risk of flashover is at its peak due to several critical factors. As the fire progresses from the ignition stage, the heat generated increases substantially, leading to the rapid combustion of adjacent combustible materials. During this stage, the fire is accumulating enough heat and smoke, creating conditions that can lead to a sudden and dramatic flashover event.

At this stage, the temperatures rise significantly, often reaching levels that allow for the ignition of the upper layer of smoke and gases. When the heat and fuel concentration become optimal, flashover can occur, which results in almost simultaneous ignition of combustible materials in the room. Understanding this critical moment is essential for firefighters, as it dictates tactics and safety measures when combating a fire.

The ignition stage is simply the starting point where a fire begins, and the decay stage represents a decline in fire activity as fuel is consumed or conditions become less favorable for combustion. The fully developed stage is characterized by a sustained and intense fire but is usually past the peak risk for a flashover, as the conditions have already reached a point of full involvement. This makes the growth stage uniquely critical for understanding and anticipating fire behavior.