What is the primary purpose of using Class A foam on hydrocarbon spills?

• A. To reduce surface tension and improve water penetration into the fuel.
• B. To create a chemical barrier that seals the spill immediately.
• C. To burn off the fuel surface.
• D. To dry the spill quickly.

Answer: (A)

Class A foam acts as a wetting agent. Its main purpose on a hydrocarbon spill is to lower the surface tension of water so the water can spread more easily and penetrate into the fuel layer. This improves cooling and heat absorption, helping to slow vapor release and make the spill easier to control. It doesn’t seal the spill, burn the fuel away, or dry it out—that’s not what this foam is designed to do.