Aqueous Film-Forming Foam (AFFF) is a type of firefighting foam used to suppress flammable liquid fires, such as those involving gasoline or oil. It works by creating a film that spreads over the surface of the liquid, cutting off the oxygen supply and preventing the fire from reigniting. AFFF is commonly used in airports, military bases, and industrial facilities due to its effectiveness in quickly extinguishing fires. The foam is typically made from a mixture of water, surfactants, and other chemicals that help it form a stable film. While AFFF is effective, concerns have been raised about its environmental impact, particularly regarding certain per- and polyfluoroalkyl substances (PFAS) found in some formulations, which can contaminate water sources and pose health risks.