In which stage of the burning process does flameover occur?

Flameover occurs during the explosive growth stage of the burning process. At this stage, the availability of combustible materials and oxygen, along with the temperatures reached, create conditions for rapid fire spread. The term "flameover" specifically refers to the moment when flames spread rapidly throughout the environment, often attributed to the ignition of the accumulated smoke and gases at high temperatures.

In this scenario, the fire may have consumed most of the oxygen in its immediate environment, and when additional oxygen is introduced—either through structural openings or other means—the fire can reignite rapidly, resulting in a dramatic increase in flames. Understanding this stage is crucial for firefighters, as it presents significant hazards and requires strategic firefighting techniques to manage the fire effectively and protect against potential flashover scenarios.

Other stages, such as ignition and initial growth, involve the foundational development of the fire without the intense energy release seen during explosive growth. The ventilation-limited stage, while also critical, generally focuses on the challenges associated with limited oxygen availability rather than the rapid spread of flames.