AFFF (Aqueous Film-Forming Foam)
PFAS-containing firefighting foam used to suppress fuel fires, a major source of groundwater contamination.
Aqueous film-forming foam is a fire suppressant designed for hydrocarbon fuel fires (Class B). AFFF contains PFOS and other PFAS that spread a thin film over burning fuel. Decades of use at military bases, airports, and fire training areas have created widespread soil and groundwater contamination plumes, making AFFF sites among the most heavily contaminated PFAS locations.