Frank Granados was training with the Tucson Fire Department when a new firefighting product was introduced at the site. After igniting a pool of JP-4 jet fuel, the crew deployed the product, a type of foam, and extinguished the fire in about 40 seconds, nearly twice as fast as anything they’d used before.
“It put out fire like nobody’s business. Incredible stuff,” said Granados, now a senior advisor for the Rio Rico Medical and Fire District, which serves the town about 15 miles north of the Arizona-Mexico border.
It also smelled better than the protein-based foam they were using before, which had animal blood in it. After that trial in the 1980s, the department kept both foams on hand, but in Tucson and across the country, Aqueous Film Forming Foam, or AFFF, became the standard for handling flammable liquid fires, known as Class B fires, for half a century.