Which concentration is sometimes used in foam systems besides 3% and 6%?

• A. 8%
• B. 9%
• C. 2%
• D. 1%

Answer: (D)

Foam systems are designed to mix a foam concentrate with water at a specified proportion, and that proportion is dictated by the foam product’s data sheet and the hazard being protected. While 3% and 6% are the most common mix rates, some foam concentrates are formulated to be effective at a lower concentration, such as 1%. In those cases, the proportioning equipment and procedures are set to deliver roughly one part concentrate to 99 parts water. Using the lower percentage can reduce foam solution volume, save water, and still provide the required foam blanket and drainage for certain fuels or configurations. The key is that the chosen concentration must come from the foam supplier’s specifications and be compatible with the system’s proportioner, nozzle, and discharge devices.