There are estimated to be more than 9,000 PFAS chemicals. Some of the most common include Perfluorooctane Sulfonate (PFOS) and Perfluorooctanoic Acid (PFOA), also known as C8. These chemicals were once widely used in substances like fabric and leather coatings, household cleaning products, firefighting foams, and stain-resistant carpeting. Although manufacturers have phased out their use in Canada and the U.S. over the past two decades, they remain ubiquitous in the environment—and in our bodies. Dupont developed GenX as a replacement for PFOA in 2009, but subsequent studies of GenX have also raised health concerns. Polytetrafluoroethylene (PTFE), along with C8/PFOA, were used to produce Teflon, the non-stick chemical coating manufactured for decades by Dupont and now Chemours, which Dupont spun off in 2015.