What is the transition phase during a compartment fire where all contents reach their ignition temperature called?

The transition phase during a compartment fire where all contents reach their ignition temperature is known as flashover. This phenomenon occurs when the temperature in the compartment rises to a critical point, typically around 1,100°F (593°C), leading to simultaneous ignition of combustible materials in the space. During flashover, surfaces in the room become hot enough to ignite, creating a rapid and intense fire that can spread rapidly throughout the entire compartment.

Understanding flashover is essential in fire response training because it represents a significant shift in fire behavior, indicating that conditions have become extremely dangerous for any occupants and firefighters present. Recognizing the signs of an impending flashover, such as high heat levels and the presence of thick smoke, is crucial for safety and effective firefighting strategy. This phase is a critical point in fire dynamics and significantly affects how firefighters approach their tactics in a structural fire scenario.