What is the recommended foam concentrate to water ratio for AFFF?

The recommended foam concentrate to water ratio for Aqueous Film Forming Foam (AFFF) is typically in the range of 3% to 6%. This concentration is critical for effectively suppressing petroleum-based fires. At this ratio, AFFF creates a thin, aqueous film that spreads over the burning surface, smothering the fire and preventing the release of flammable vapors.

Using a 3% to 6% concentration maximizes the foam's efficiency. It ensures adequate coverage and the formation of a stable foam blanket that can extinguish fires while also providing a barrier to re-ignition. This concentration is widely accepted and utilized in both training and real-life firefighting scenarios at airports, where fuel fires may occur.

In contrast, lower concentrations would not provide sufficient fire suppression capabilities, while higher concentrations could result in waste and potential environmental concerns without significantly improving firefighting effectiveness. Thus, maintaining the correct ratio is essential for optimal performance in fire suppression efforts.