What is the stage of a fire called when all surfaces and objects within a space have reached their ignition temperature?

The stage of a fire when all surfaces and objects within a space have reached their ignition temperature is referred to as flashover. This phenomenon occurs when the environment becomes so heated that the materials within it spontaneously ignite almost simultaneously. It typically happens in enclosed spaces where heat has accumulated, creating a rapid transition from a relatively smaller fire that may be burning actively to a fully engulfed fire.

During flashover, radiant heat from the fire causes surrounding items and surfaces to reach their ignition temperature, which can lead to a sudden and explosive spread of the flames throughout the entire area. This stage is critical for fire investigators to understand, as it significantly influences fire behavior and the development of the fire scene.

Other stages such as rollover, backdraft, and premixed flame represent different fire dynamics. Rollover describes the ignition of gases that accumulate at the ceiling level, backdraft refers to a dangerous condition that can occur when a fire has used up most of its oxygen but can reignite explosively when oxygen is reintroduced, and a premixed flame involves a specific combustion scenario where the fuel and oxidant are mixed before ignition. Each of these stages has its own characteristics and implications in fire scenarios but does not specifically represent the point where everything ignites that defines flash