During which stage of a fire is the maximum heat release rate achieved?

The maximum heat release rate during a fire occurs during the fully developed phase. At this stage, the fire has consumed the available fuel and oxygen to reach its peak intensity. This phase is characterized by a fully involved fire, where combustion is at its most efficient due to optimal conditions for burning.

In this phase, the temperature is also at its highest, and not only is the heat output maximized, but smoke production is also significant. The fully developed phase is critical for firefighters to understand, as it indicates the most dangerous and uncontrollable state of the fire. Firefighters must recognize this stage to implement effective strategies for suppression and to protect themselves from the extreme conditions present.