Protecting Firefighters from Adverse Substances Act or the PFAS Act This bill requires the Department of Homeland Security (DHS) to develop guidance for firefighters and other emergency response personnel on training, education programs, and best practices to protect them from exposure to perfluoroalkyl and polyfluoroalkyl substances, commonly referred to as PFASs, from firefighting foam and to prevent the release of PFASs into the environment. These substances are man-made and may have adverse human health effects. A variety of products contain the compounds, such as nonstick cookware or weatherproof clothing. DHS shall make available a curriculum designed to reduce and eliminate exposure to PFAS from firefighting foam and personal protective equipment (PPE); prevent the release of PFAS from firefighting foam into the environment; and educate firefighters and other emergency response personnel on foams and non-foam alternatives, PPE, and other firefighting tools and equipment that do not contain PFAS. The U.S. Fire Administration shall make recommendations to DHS on the content of the curriculum. DHS must create an online public repository containing tools and best practices to reduce, limit, and prevent the release of and exposure to PFASs.