How is flashover defined in fire service terminology?

Flashover is defined as the rapid transition of a fire, where all combustible materials within a room or contained space reach their ignition temperature at nearly the same moment. This phenomenon occurs due to the accumulation of heat and the presence of sufficient fuel, combining to create an explosive growth phase in the fire.

Once flashover occurs, the fire can become uncontrollable and extremely dangerous, as it can lead to a significant increase in fire intensity and the rate at which it spreads. Firefighters must understand this concept to effectively assess risks and make strategic decisions during fire operations. Recognizing the signs leading up to a potential flashover, such as high heat, smoke conditions, and the arrangement of materials, is crucial for ensuring the safety of both personnel and occupants in the structure.

While the other definitions may describe related fire scenarios, they do not capture the specific phenomenon of flashover that is characterized by the simultaneous ignition of all contents in a room.