PFAS are a very large group of synthetic chemicals that includes PFOA, PFOS, GenX chemicals, and potentially more than 4,000 other compounds that have been manufactured and used in a variety of industries worldwide since the 1940s. PFAS are found in a wide array of consumer products and industrial processes, including firefighting foams, chemical processing, building/construction, aerospace, electronics, semiconductor and automotive industries, stain- and water-resistant coatings, food packaging, and waxes and cleaners. Due to their strong carbon-fluorine bonds, many PFAS can be very persistent in the environment with degradation periods of years, decades, or longer. Most people in the United States have been exposed to these molecules, and there is evidence that continued exposure to certain PFAS above specific levels may lead to adverse health effects, such as developmental effects, cancer, liver effects, immune effects, and thyroid effects. As a result, the characterization, regulation and remediation of PFAS has become a primary focus of regulatory bodies around the world.