PFAS stands for per-and poly-fluoroalkyl substances. These substances are manufactured chemicals that have been used since the 1950s to make products that resist heat, oil, stains and water.
Due to their effectiveness in fighting liquid fuel fires, firefighting foams containing perfluorooctane sulfonate (PFOS) and perflurorooctanic aid (PFOA) as active ingredients were once used extensively worldwide and within Australia, including at civilian airports. Perfluorohexane sulfonate (PFHxA) is also commonly found in legacy firefighting foams as an impurity in the manufacuturing process.
PFOS, PFOA and PFHxA belong to the PFAS group of chemicals.
PFAS have also been used in Australia and around the world in many common household products and specialty applications. As a result, most people living in developed nations have a detectable level of PFAS in their blood. The release of PFAS into the environment is a concern, because these chemicals are highly persistent, have been shown to be toxic to fish and some animals, and can accumulate in the bodies of fish, animals and people who come into contact with them. However currently there is limited evidence that exposure to PFAS causes adverse human health effects.
In 2003 Airservices Australia, the government's air navigation service provider, commenced phasing out its use of legacy firefighting foam containing PFOS and PFOA as active ingredients and transitioned to a more environmentally safe product. In 2010 it ceased using fluorine containing foams and switched to fluorine free foam.