What does backdraft mean?
A backdraft is a current of air that moves in the opposite direction to the expected or intended flow. Its best-known meaning concerns fire safety: when air enters a confined, heat-filled space through an opening, it can provide the oxygen needed for combustion to accelerate suddenly, potentially causing flashover. This makes doors, windows, and other structural openings important considerations for firefighters. The word also has a broader technical use for any reverse flow of air, including in chimneys, ducts, and ventilation systems. Outside these specialized contexts, it is uncommon and can sound technical or metaphorical. In British English, the related spelling “backdraught” is prevalent, whereas “backdraft” is particularly associated with North American usage. The term is memorable because a seemingly small change in airflow can have dramatic consequences in a fire.
nounA current of air flowing in the opposite direction to the intended or prevailing flow, especially an inward rush of air into a fire-filled space. Such a reversal can cause sudden ignition or flashover.
- A rapid reversal of airflow into an enclosed or fire-filled space, capable of causing sudden combustion or flashover.
- A current of air moving opposite to the intended or prevailing direction, as in a ventilation system, chimney, or other enclosed space.
"The firefighter said that opening the front door had created a dangerous backdraft inside the house."
"The crew kept the front door closed because an open doorway could produce a backdraft."
"A reverse current in the ventilation shaft created a backdraft that scattered dust throughout the room."
The regular plural is backdrafts, though the word is usually used in the singular when referring to a particular event.
"The report described two backdrafts during the early stages of the fire."
A backdraft can turn a doorway into a fuse: a sudden influx of oxygen may trigger flashover before firefighters can act.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does backdraft come from?
Backdraft is an English compound formed from “back” and “draft,” an older word for a current of air. The compound was initially used for a reverse airflow and was later especially associated with the dangerous behavior of fires; “draft” is related to “draw” in its older sense of pulling or drawing something.
How backdraft is actually used
The term is most common in fire safety, building ventilation, and related technical contexts. In British English, “backdraught” is the usual spelling, while “backdraft” is especially common in North American usage.
Easily confused with backdraft
A backdrop is the background or setting of a scene or situation, whereas a backdraft is a reversal in the direction of airflow.