Candidate Physical Ability Test (CPAT) Practice Test

True or False: Class A foam provides superior knockdown on ordinary combustible materials.

1. True

2. False

3. Only for flammable liquids

4. Depends on the foam concentration

The correct answer is: True

Class A foam is specifically designed to enhance the effectiveness of water when fighting ordinary combustible materials, such as wood, paper, and other common fuels. It does this by reducing the surface tension of water, allowing it to penetrate more thoroughly into burning materials. This improved penetration helps to cool and extinguish the fire more effectively than water alone. When applied correctly, Class A foam can create a barrier that suppresses steam and helps control the release of flammable vapors while providing a cooling effect. This unique property is what contributes to the superior knockdown capabilities of Class A foam compared to other extinguishing agents for ordinary combustibles. Therefore, the statement about Class A foam providing superior knockdown on ordinary combustible materials is true.