What happens during a backdraft in a fire scenario?

During a backdraft scenario, a fire that has been starved of oxygen can build up combustible gases over time. When oxygen is suddenly introduced—such as when a door or window is opened—these gases ignite rapidly, leading to an immediate and violent explosion. This phenomenon occurs because the prior lack of oxygen prevents flames from sustaining themselves, but the presence of additional oxygen allows the accumulated gases to combust explosively.

The dynamics of backdraft are critical for fire safety and response tactics. Understanding that an influx of oxygen can cause such explosive results is essential for firefighters to manage the situation safely, often involving techniques to ventilate smoke and heat before fully opening an area. The other scenarios do not capture the immediate life-threatening nature of backdraft effectively, as slow burns or effects like flaming or ghosting do not denote the explosive risks associated with sudden oxygen introduction during a fire.