AFFF stands for Aqueous Film Forming Foam. AFFF is stored as a liquid and discharged as a foam which covers the area in the spray pattern to extinguish the flames and cool the area to suppress re-ignition. AFFF is non-conductive and non-corrosive, environmentally friendly, and it cleans up with water. It is accepted by most race sanctioning bodies including SCCA, FIA, and IMSA. SCCA requires SFI- or FIA-approved systems in all new racecars. These systems are also legal for all other cars.