What is the maximum recommended concentration for Class A foam?

What is the maximum recommended concentration for Class A foam?

• A. 0.75%
• B. 0.5%
• C. 0.9%
• D. 1%

Answer: (D)

Class A foam works by lowering the surface tension of water and creating a foam blanket that cools and penetrates ordinary combustibles, improving wetting and reducing the chance of reignition. The foam concentrate must be diluted with water to a specific percent, and there is an upper limit to this dilution set by the product’s instructions. That upper limit is 1 percent. Staying at or below this cap ensures you gain the benefits of enhanced wetting and cooling without creating excessive foam that can hinder visibility, reduce stream reach, or waste concentrate. While many operations use lower concentrations like 0.1 to 0.5 percent, the maximum allowed concentration to follow for Class A foam is 1 percent.

Class A foam works by lowering the surface tension of water and creating a foam blanket that cools and penetrates ordinary combustibles, improving wetting and reducing the chance of reignition. The foam concentrate must be diluted with water to a specific percent, and there is an upper limit to this dilution set by the product’s instructions. That upper limit is 1 percent. Staying at or below this cap ensures you gain the benefits of enhanced wetting and cooling without creating excessive foam that can hinder visibility, reduce stream reach, or waste concentrate. While many operations use lower concentrations like 0.1 to 0.5 percent, the maximum allowed concentration to follow for Class A foam is 1 percent.