Durpro, Raphael Bouchard-Tremblay What are Perfluoroalkyl and Polyfluoroalkyl Substances? PFAS are a group of about 4700 synthetic substances used as surfactants, lubricants and repellents for dust, water, and grease. They can also be found in firefighting foams, some textiles, cosmetics, ... Contaminant May 3, 2023