What is the typical oxygen content reduction percentage during the growth stage of a fire?

During the growth stage of a fire, there is a significant increase in flame and heat production, which consumes a large amount of oxygen. The oxygen content in the atmosphere typically reduces by about 16-20% during this phase. This reduction occurs as fuel ignites and begins to burn rapidly, drawing in oxygen to sustain combustion. This process highlights the importance of oxygen in maintaining fire behavior; as the oxygen level decreases, fire conditions can change, affecting the fire's intensity and potentially leading to smoke production and toxic gas generation.

The selected range accurately reflects the expected decrease in oxygen during this critical stage of fire development, where the fire is building up in intensity and reducing the available breathable air in its vicinity. Understanding this percentage can help firefighters anticipate fire behavior, assess safety risks, and make informed decisions during firefighting operations.