Decay stage begins after which stage?

Decay stage begins after which stage?

• A. Growth stage
• B. After the growth stage
• C. Fully developed
• D. Incipient

Answer: (B)

Fire behavior in a compartment progresses through stages, and the decay stage follows the peak of the fire. The growth stage is when the fire is increasing in intensity and heat release. The fully developed stage is the point of maximum heat release and total involvement of the compartment’s fuels. After that peak, the decay stage begins as fuels are consumed and ventilation or oxygen availability changes, causing the heat release to decline. So the decay stage comes after the fully developed stage, not right after the growth stage. The option describing decay as occurring after the growth stage would place the decline before the fire has reached its maximum intensity.

Fire behavior in a compartment progresses through stages, and the decay stage follows the peak of the fire. The growth stage is when the fire is increasing in intensity and heat release. The fully developed stage is the point of maximum heat release and total involvement of the compartment’s fuels. After that peak, the decay stage begins as fuels are consumed and ventilation or oxygen availability changes, causing the heat release to decline. So the decay stage comes after the fully developed stage, not right after the growth stage. The option describing decay as occurring after the growth stage would place the decline before the fire has reached its maximum intensity.