What can be expected as oxygen content in a fire scene decreases?

As oxygen content in a fire scene decreases, the expected outcome is that flames will extinguish gradually. Fires require a certain concentration of oxygen to sustain combustion. When the oxygen level drops, the fire’s ability to maintain its flames diminishes, leading to a gradual reduction in the intensity of the fire.

This decrease in oxygen can result from various factors, such as the enclosure of a space, the burning of available fuel, or the introduction of suppression agents. As the oxygen level continues to fall, the fire will not extinguish instantaneously; rather, it will burn less vigorously and transition to lower combustion states until it finally goes out.

The other options do not accurately represent the typical response of a fire to decreasing oxygen levels. For instance, while a fire may eventually extinguish, it does not do so immediately, nor does it lead to a significant decrease in the likelihood of flashover or a continuation of the free-burning phase, which typically requires a sufficient oxygen supply.