The AFFF foam solution is rated for applications of what percentage to what percentage?

• A. 3% to 6%
• B. 6% to 9%
• C. 1% to 3%
• D. 0.5% to 1.5%

Answer: (A)

Foam solution strength is the percent concentrate mixed with water to create the firefighting foam. For AFFF used on hydrocarbon fires, the standard application range is 3% to 6%. This means mixing 3 to 6 gallons of concentrate per 100 gallons of foam solution, creating a thicker, longer-lasting foam blanket that rapidly covers the fuel surface, cools the fuel, and helps suppress vapors. At the lower end (around 3%), you get effective coverage for smaller or less intense fires; at the higher end (around 6%), you gain a stronger blanket suitable for larger spills or more demanding fires. The other ranges are associated with different fuels or foam products and aren’t typical for hydrocarbon fires with AFFF. Always follow the manufacturer’s instructions for the specific concentrate you’re using.