In which phase of a compartmentalized fire do conditions exist where open flaming decreases because smoke production displaces and limits available combustion air?

The Ventilation-Limited Phase is characterized by conditions where open flaming decreases due to the displacement and limitation of available combustion air by smoke production. In this phase, the fire is starved of oxygen, as the smoke that accumulates in the compartment reduces the amount of air required for combustion. As the oxygen concentration drops, flames are suppressed, and the fire struggles to sustain itself.

During this phase, the heat and smoke created by the fire combine to create an environment that has very limited fresh air intake, which contributes to the decrease in open flaming. It's a critical phase to understand because fire behavior changes significantly: firefighters must consider the risks of flashover and backdraft when ventilation is introduced, as it can suddenly reactivate the fire.

In contrast, the Growth Phase typically involves an increase in fire size and intensity as the fire spreads, while the Fully Developed Phase indicates a mature fire that is fully involved and active. The Decay Phase follows the peak of the fire, where it begins to go out due to the depletion of available fuel or oxygen. Understanding these phases is essential for safety officers in planning effective firefighting strategies and ensuring the safety of personnel.