Prevent Future American Sickness Act of 2020 This bill requires the Environmental Protection Agency (EPA) to designate all perfluoroalkyl and polyfluoroalkyl substances, commonly referred to as PFAS, as hazardous substances within one year of enactment of this bill. PFAS are man-made and may have adverse human health effects. A variety of products contain the compounds, such as nonstick cookware or weatherproof clothing. The bill authorizes states to provide grants to owners of household water wells that have been contaminated by PFAS to purchase and install a household filtration system. Among other requirements, the EPA must establish pretreatment standards for PFAS introduced into publicly owned treatment works; implement various grant programs to assist with PFAS contamination, water infrastructure, and PFAS pretreatment standards; issue a final rule adding PFAS to the list of hazardous air pollutants and, within one year after issuing the rule, revise the list of air pollution sources to include categories and subcategories of major sources and area sources of PFAS; prohibit the disposal of firefighting foam (containing PFAS) by incineration; and identify additional wastes containing PFAS for which a prohibition on incineration may be necessary and prescribe such prohibitions. The bill bans the use of PFAS in food contact substances, which are substances intended for use as a component of materials in manufacturing, packing, packaging, transporting, or holding food, if such use is not intended to have a technical effect in such food. For criminal penalty purposes, wastes containing PFAS must be considered hazardous waste.