What does the term 'flashover' refer to in fire dynamics?

The term 'flashover' refers to a critical moment in fire dynamics characterized by a sudden and rapid increase in temperature throughout a room or an enclosed space, which leads to the ignition of combustible materials present in that area. During a flashover event, the heat accumulated from the fire can cause the temperature to rise dramatically, often reaching levels that can ignite all of the combustible materials in the room simultaneously.

The phenomenon occurs when the temperature reaches a threshold that allows for the airborne gases and nearby combustibles to ignite in unison, leading to an intense and widespread fire. This effectively transitions a fire from a localized event to one that engulfs the entire room, marking a dramatic moment in the growth and spread of a fire. Understanding flashover is critical for fire investigators and firefighters in assessing the danger posed by a fire and in developing strategies for safe firefighting procedures and accurate investigations of fire origins and causes.