Class A foams are formulated to be mixed with water in ratios from __________%.

Class A foams are specifically designed for use on ordinary combustible materials such as wood, paper, and some plastics. They work by enhancing the water's ability to penetrate and cool the burning materials. The recommended mixing ratios for Class A foams typically range from 0.1% to 1.0%. This means that very low concentrations are effective in creating a foam blanket that reduces fuel exposure to oxygen, thus extinguishing the fire while also cooling the surface temperatures.

When mixed within this range, the foam produces a stable solution that can effectively suppress fires by smothering them and preventing re-ignition. Understanding the appropriate mixing ratios is crucial for firefighters and emergency responders to ensure the effectiveness of the foam at various fire incidents.