Class A foam is typically mixed in what concentration?

Class A foam is designed specifically for combating ordinary combustible fires and is typically used in a concentration of 0.1% to 1%. This relatively low concentration is effective for enhancing the wetting capabilities of water, allowing it to penetrate burning materials more effectively than water alone.

Using this concentration facilitates the reduction of surface tension in water, which helps the liquid to spread and soak into combustible fuels. This is particularly crucial when dealing with materials such as wood, paper, and textiles. With Class A foam functioning optimally at this concentration range, it can suppress fires more quickly and efficiently, resulting in improved fire control and reduced water usage.

Understanding the application of Class A foam and its correct concentration is critical for pump operators, as improper mixing ratios can lead to decreased effectiveness, potentially prolonging firefighting efforts and increasing risk.