What stage of fire occurs when flames have spread to the entirety of the room?

The stage of fire where flames have spread throughout the entirety of the room is known as post flashover. In this phase, the fire has reached a critical point where it has transitioned from an incipient stage to a fully developed fire, resulting in a rapid and extensive spread of flames throughout the room.

During this stage, the temperature can increase significantly, and smoke production is at its peak. Post flashover indicates that all combustible materials in the vicinity have been ignited, creating an intense environment with high heat and rapid combustion. It is characterized by the simultaneous ignition of fuels at different points in the room, leading to full room involvement. Understanding this stage is crucial for fire investigators as it helps them assess the extent of damage, determine the fire's growth pattern, and evaluate potential causes of ignition.