Which fire extinguishing agent can effectively cool burning materials and suppress flames?

Foam is an effective fire extinguishing agent primarily because it creates a blanket over the burning material, both cooling it and suffocating the flames. This dual action is particularly important in suppressing liquid fires, where the foam can effectively separate the fuel from the oxygen in the surrounding air. The cooling effect helps to reduce temperatures, preventing reignition, while the foam can also suppress vapor emissions, thus minimizing the potential for fire spread.

While carbon dioxide is effective for certain types of fires, it primarily works by displacing oxygen and might not sufficiently cool the burning materials. Halon, similar to carbon dioxide, acts by interrupting the chemical reaction of combustion but does not provide a significant cooling effect. Dry powder agents may suppress flames effectively but generally do not provide the cooling effect that foam does. Therefore, foam is the most comprehensive choice for cooling burning materials while suppressing flames.