Perfluorooctanoic acid (PFOA), also known as C8 and perfluorooctanoate. Perfluoroalkyl substances (PFASs) are also known as perfluorochemicals (PFCs). Understanding the existence of PFASs in the environment is important because they are the most widespread and persistent manmade chemicals on earth. Some of the most common products that contain PFASs are Teflon pans, non-stick cookware, rain/waterproof jackets (like Gore-Tex), fire-fighting foams, food packaging, carpets, and furniture fabrics. PFASs stay in the environment for a long period of time. Long environmental residence time means that, like other persistent chemicals (such as DDT), PFASs can accumulate in organisms to levels that cause harmful effects.

PFASs are present in many environmental matrices, such as water, sediments, and wildlife (Houde et al. 2011). They are toxic (harmful) to vertebrates such as fish, birds, and mammals at certain concentrations. Two PFASs—perfluorooctanoic acid (PFOA) and perfluorooctanoic sulfonate (PFOS)—are so widespread that they are believed to be present in the blood, breast milk, kidneys, and liver of every person (Kannan et al. 2004).