What is the purpose of cutting off oxygen in a fire scenario?

Cutting off oxygen in a fire scenario is essential because fire requires three elements to sustain itself: heat, fuel, and oxygen, known as the fire triangle. By removing or limiting the supply of oxygen, you effectively smother the fire, which prevents it from continuing to burn. Most fires need a minimum concentration of oxygen to thrive, typically around 16%. When you reduce the oxygen level below this threshold, the combustion process cannot continue, leading to the extinguishing of the flames.

In the context of firefighting strategies, methods such as using foam, certain types of fire extinguishers, or even covering burning materials with non-flammable objects work on this principle. This approach is crucial in both firefighting and fire prevention as it targets the very conditions that allow fires to propagate.