What percentage for polar solvents when using Class A foam?

• A. 9%
• B. 12%
• C. 6%
• D. 3%

Answer: (C)

When fighting fires with polar solvent fuels, you need a stronger, more persistent foam blanket. Polar solvents evaporate quickly and spread on the surface, making it easy for vapors to reignite. Using Class A foam at a higher concentration helps the foam form a stable, continuous film that covers the liquid surface, cools it, and keeps vapors from escaping. That durable film is what provides effective suppression for these challenging solvents, which is why a higher concentration is recommended. Lower concentrations won’t maintain the film or coverage as well, while extremely high concentrations aren’t usually necessary in typical scenarios.