A concentrated aqueous solution of one or more hydrocarbon and/or fluorochemical surfactants that forms a foam capable of producing a vapor-suppressing, aqueous film on the surface of hydrocarbon fuels
NFPA 403 Standard for Aircraft Rescue and Fire-Fighting Services at Airports, 2009 ed. http://www.nfpa.org/assets/files/aboutthecodes/403 /403-a2013-rop.pdf, (Std: Aircraft Rsq and Fr Fight Srvc at Airpt - Amer) {302 NFC}