Which stage results from a decrease in the fuel load or available oxygen?

Which stage results from a decrease in the fuel load or available oxygen?

• A. Decay phase.
• B. Incipient stage.
• C. Growth phase.
• D. Fully developed stage.

Answer: (A)

In fire behavior, stages show how a fire evolves as heat, fuel, and oxygen interact. When fuel is reduced or the amount of oxygen available drops, the fire cannot sustain high heat release, so it enters the decay phase. Temperatures fall, flames diminish, and the fire may shift toward smoldering as it loses the energy it needs to keep burning vigorously. The other stages describe earlier or peak activity: the incipient stage is the start of ignition and initial growth, the growth stage is rapid expansion with abundant fuel and oxygen, and the fully developed stage is when the fire has reached its maximum size and heat output. So, the stage that results from a decrease in fuel load or available oxygen is the decay phase.