What can happen if a new supply of oxygen is introduced during the smoldering phase?

Introducing a new supply of oxygen during the smoldering phase can lead to the fire rekindling and re-entering the free-burning stage. In the smoldering phase, combustion is occurring at a slow rate, primarily producing heat and smoke rather than flames. This phase is characterized by low oxygen levels and insufficient energy to sustain vigorous burning.

When additional oxygen is introduced, it provides the necessary element for combustion to accelerate. If the oxygen supply increases, it can invigorate the smoldering material, leading to an increase in heat and potentially reigniting flames. This transition signifies a shift from a controlled, smoldering condition back to an active, free-burning state, which poses a significant risk, especially in firefighting contexts. Therefore, understanding the link between oxygen supply and fire behavior is crucial in managing and extinguishing fires effectively.