During which event might backdraft occur?

Backdraft is a dangerous phenomenon that occurs in a fire situation when oxygen is suddenly introduced to an enclosed space filled with heated gases. This typically happens when a door or window is opened, or when a breach occurs in the structure allowing fresh air to enter. The existing hot gases, which have not fully combusted due to a lack of sufficient oxygen, can ignite explosively when additional oxygen is available. This rapid combustion can lead to an explosive fireball, posing a significant risk to anyone nearby.

Understanding backdraft is critical for firefighters as it can greatly influence the tactics used during firefighting operations. Recognizing the signs of a potential backdraft, such as smoke being drawn into openings or lingering hot gases, can help firefighters take necessary precautions to avoid triggering this explosive reaction.