The sudden introduction of air into an oxygen-depleted, superheated space may lead to what phenomenon?

The phenomenon that occurs when air is suddenly introduced into an oxygen-depleted, superheated environment is known as backdraft. This occurs when a fire has consumed most of the available oxygen, causing the flames to die down or smolder. When a door or window is opened, fresh air rushes into this space, potentially igniting the remaining combustibles and creating a sudden and violent flare-up. The rapid increase in available oxygen accelerates the combustion process, often resulting in a powerful explosion of flames that can be very dangerous to those nearby.

The other phenomena listed are related to fire dynamics but differ in their specific conditions and characteristics. For example, flashover refers to the rapid spread of fire when all combustibles in a room reach their ignition temperature simultaneously, but it requires a different set of conditions involving the heating of materials rather than the sudden introduction of air. A fire whirl is a rotating column of flames that occurs in certain wind conditions, and a smoke explosion is an event characterized by the ignition of smoke-filled spaces; both are distinct from the scenario described in the question.