What is the primary purpose of using Class A foam?

The primary purpose of using Class A foam is to suppress fires in ordinary combustibles. Class A foam is specifically formulated for use on materials such as wood, cloth, paper, and other common firefighting scenarios. It enhances the water's effectiveness by lowering the surface tension, allowing it to penetrate more deeply into the burning materials. This increased penetration helps cool the fire and extinguish it more effectively.

When applied to ordinary combustibles, Class A foam forms a blanket over the surface, which helps to prevent re-ignition and can cool down the adjacent materials that may also catch fire. It is important to differentiate this from other types of firefighting foams, which are designed for specific uses, such as flammable liquids or special situations like wildland fires.