Which Class B foam is specified at 1%, 3%, and 6% concentrations?

• A. Protein foam
• B. Fluoroprotein foam
• C. Film forming fluoroprotein foam (FFFP)
• D. Aqueous Film Forming Foam (AFFF)

Answer: (D)

The key idea is that different Class B foams have different usable dilution ranges, and AFFF uniquely offers effective performance across a wider set of concentrations. Aqueous Film Forming Foam forms a protective film on the fuel surface and spreads readily due to its surface-active components, allowing reliable firefighting action at 1%, 3%, and 6% dilutions. This flexibility lets responders tailor the foam blanket to the fuel type, fire size, and water supply. Other foams, like protein or fluoroprotein types, are typically used at a narrower range (often around 3% or 6%), with 1% not being a standard option for them. So the foam specified for 1%, 3%, and 6% is AFFF.