Which phase follows ignition and is marked by rapid growth if heat is supplied?

Which phase follows ignition and is marked by rapid growth if heat is supplied?

• A. Growth
• B. Decay
• C. Fully developed
• D. Ignition

Answer: (A)

The key idea is how a fire behaves after it has ignited when heat continues to feed the flames. After ignition, the fire enters a growth phase, where the heat released increases and more fuels reach ignition. With sustained heat input, this phase shows rapid expansion of the flames and a rising heat release rate, as the fire rapidly grows bigger before any major changes in ventilation or fuel occur. This stage sits between ignition and fully developed fire, and it’s marked by accelerating growth rather than peak spread or cooling. Decay comes later when fuels are exhausted or cooling slows the fire, while fully developed is when the fire has reached its maximum extent in the environment.

The key idea is how a fire behaves after it has ignited when heat continues to feed the flames. After ignition, the fire enters a growth phase, where the heat released increases and more fuels reach ignition. With sustained heat input, this phase shows rapid expansion of the flames and a rising heat release rate, as the fire rapidly grows bigger before any major changes in ventilation or fuel occur. This stage sits between ignition and fully developed fire, and it’s marked by accelerating growth rather than peak spread or cooling. Decay comes later when fuels are exhausted or cooling slows the fire, while fully developed is when the fire has reached its maximum extent in the environment.