If Agneta Bruno closes her eyes, the soapy smell takes her back to childhood. Cycling home to the barracks where she lived with her father, an air force major, she would whiz through patches of snowy-white foam near the entrance of the base. The foam resembled the bubbles you get in the bathtub, just thicker. “I had to lift my feet up to avoid getting wet,” Bruno told me.
Aqueous film-forming foam (Afff) is a miracle of firefighting: it’s highly effective in putting out flammable liquid fires, such as those caused by jet fuel spills. Chemicals in the foam create a stable blanket over liquid fuel, trapping the flammable vapours and extinguishing the fire. At the air force base in Bruno’s home town of Kallinge in Sweden, firefighters were trained to douse flames using the foam. New recruits came every few weeks, so the training sessions were pretty constant. Afterwards, the foam would soak away into the sandy soil and disappear.
