Most fire fighting foams are intended to be mixed with what percentage of water?

• A. 60 Percent Water
• B. 10 Percent Water
• C. 50 Percent Water
• D. 94 To 99.9 Percent Water

Answer: (D)

Foam solutions are created by mixing a small amount of foam concentrate with a large amount of water, so the finished mix is mainly water. The concentrate supplies the surface-active agents and other properties that let the foam form and cling, while the water provides cooling, heat absorption, and the foam blanket needed to shield the fire. Because only a small fraction of concentrate is required, the water content in typical foam solutions is about 94% to 99.9%. The other percentages would imply far more concentrate and would not reflect how most firefighting foams are designed to operate.