Which item best aids extinguishment of smoldering fires and tightly packed materials?

Which item best aids extinguishment of smoldering fires and tightly packed materials?

• A. Aqueous Film Forming Foam (AFFF)
• B. Class A Foam
• C. Fluoroprotein Foam
• D. Protein Foam

Answer: (B)

When you’re fighting a smoldering fire in a tightly packed pile, getting water deep into the fuel and cooling it throughout the entire mass is crucial. Class A foam is designed to wet ordinary combustibles and penetrate porous, packed fuels, creating a cooling blanket and lowering the surface tension so the water can reach embers inside the material. This deep wetting and cooling helps prevent reignition and helps extinguish smoldering piles more effectively than foams designed for liquids. Foams like AFFF or fluoroprotein/protein foams are tailored for hydrocarbon or specific liquid fires and don’t soak and cool dense solids as well, making them less suitable for smoldering, packed materials.