A spill at the Rafael Hernández International Airport in Aguadilla, Puerto Rico, has brought attention to a lesser-known substance called AFFF (aqueous film-forming foam), used to combat fuel-related fires. According to Aguadilla Mayor Julio Roldán Concepción, US Customs and Border Protection (CBP) personnel identified the spilled substance as AFFF.
The US Department of Defense describes AFFF as a foam designed to extinguish fires of flammable liquids, such as gasoline or oil, by forming a barrier that separates the flames from oxygen. AFFF has been commonly used in high-risk scenarios like airports, military bases, and refineries.
However, concerns surround AFFF due to some formulations containing PFAS (perfluoroalkyl and polyfluoroalkyl substances), a group of manufactured chemicals used for their resistance to water, oil, heat, and stains. The US Environmental Protection Agency (EPA) identifies the military, petrochemical, and aviation industries as sectors where AFFF has been used to combat flammable liquid fires.