Flashover typically occurs during what phase of fire?

Flashover is a critical stage in a fire's progression and typically occurs during the fully developed phase. This phase is characterized by the fire reaching a point where it has consumed most of the available fuel and has generated enough heat to ignite all combustible materials in the room simultaneously. During this phase, the temperature can rise rapidly, often reaching levels that can exceed 1,000 degrees Fahrenheit, creating an environment where everything in the space can ignite at once.

In a fire scenario, flashover is a dangerous event because it can happen very quickly and change the dynamics of a fire from one that may be manageable to an extremely hazardous situation. The full development of the fire means that there is a significant amount of heat and flammable gases produced, which allows for the rapid spread of flames, marking it as a pivotal moment in the life cycle of a fire. Recognizing that flashover often occurs in this phase is crucial for firefighters as it informs their strategies for controlling and extinguishing the fire safely.