What stage of fire occurs when it has used all its oxygen and fuel load?

The stage of decay in a fire is characterized by the depletion of available oxygen and fuel. During this phase, the fire is no longer able to sustain combustion at the same level as before. This results in a noticeable reduction in heat and flame intensity. As the fuel source is consumed and oxygen levels drop, combustion becomes less efficient, which can lead to a smoldering condition or even extinguishment.

In this stage, the fire is transitioning from an active burning state to one where it may be near its end. It's crucial for firefighters to recognize this stage, as it can influence tactics for both extinguishment and safety. Understanding when a fire has reached the decay stage helps in assessing the situation accurately and making informed decisions about how to approach the fire control efforts.