Which of the following stages occurs before flashover?

Flashover is a critical event in a fire's progression, indicating a rapid transition where the entire room can become engulfed in flames. The correct answer regarding which stage occurs before flashover is the initial growth stage.

In the incipient stage, ignition takes place, leading to the fire beginning to burn. As the fire grows, it enters the initial growth stage where the flames begin to spread, but it does not yet reach the critical temperatures that would lead to flashover. During this stage, the temperatures increase, and more combustible materials in the environment heat up, which sets the stage for a potential flashover.

In contrast, the explosive growth stage is characterized by a rapid increase in fire intensity and heat release, often leading directly to flashover. The fully developed stage occurs after flashover has already taken place. Understanding these stages is crucial for firefighting strategies and safety protocols.