Why is foam used in firefighting?

Foam is utilized in firefighting primarily to smother flames and prevent re-ignition. When applied, foam forms a blanket over the burning material, which effectively deprives the fire of oxygen needed for combustion. This is crucial because without oxygen, the fire cannot sustain itself or continue to burn. Additionally, the foam creates a barrier that insulates the burning substances, lowering temperatures and minimizing the chances of re-ignition, which is particularly important in firefighting operations where safety and control of the situation are paramount.

The other options do not accurately represent the primary function of foam in firefighting. While increasing water pressure or creating a chemical reaction does not align with the properties or intended uses of foam, enhancing visibility at the fire scene is not a function of foam either; it tends to obscure visibility rather than improve it. Understanding these principles highlights the importance of foam in effective fire suppression strategies.