Which stage of fire growth is defined as the fire just beginning?

• A. Growth Stage
• B. Decay Stage
• C. Incipient Stage
• D. Fully Developed

Answer: (C)

Incipient stage is the fire just beginning, starting right after ignition with flames that are small and confined to the ignition area. Heat release is starting but not yet accelerating, and the ventilation hasn’t allowed a strong, large plume, so the fire remains relatively limited. If not controlled, it can rapidly progress to the next phase as more air feeds the flames and the heat release increases. In the growth stage, flames extend and intensify, producing more heat and smoke. In the fully developed stage, the room is involved and heat release peaks, posing the highest risk of flashover. In the decay stage, fuel is exhausted or ventilation changes reduce the fire, causing flames to diminish.