Protein Foam 2 : A fire fighting foam produced by adding a liquid concentrate made from animal hooves, horns, blood, and other protein matter to water. See also: Foam
Ralph W. Burklin & Robert G. Purington, Fire Terms: A Guide to Their Meaning and Use, National Protection Association, Boston, MA 1980 USA. (Guide: Meaning and Use, Nat Prot Association Fr Srvc - Amer) {457}