Define 'backdraft' in fire safety terms.

Backdraft refers to a dangerous condition that occurs in a fire scenario when a sudden influx of oxygen is introduced to an environment that has been starved of it, typically after a fire has consumed most of the available oxygen. This influx can occur when a door or window is opened, or when the scene is otherwise disrupted in a way that allows fresh air to enter.

When a backdraft occurs, the pressure and temperature rise sharply, often leading to a rapid and violent ignition of the flammable gases that have accumulated in the area. This surge can cause fire to spread explosively, representing a significant hazard for firefighters and anyone nearby.

Understanding backdraft is crucial for fire safety training because it emphasizes the importance of controlling ventilation during firefighting operations. Recognizing the signs of a potential backdraft—such as the presence of smoke staining on surfaces, a yellow or brown-colored smoke, or a lack of visible flames—can help first responders effectively manage the scene and minimize risk.