PFAS, or polyfluoroalkyl substances, are sometimes used in grease-resistant coatings for paper, such as fast-food wrappers, candy wrappers and pizza box liners. Bag manufacturers have been addressing the issue of removing PFAS since 2006 and confirm that the grease resistant coating in the majority of microwave popping bags is not produced with PFAS.
PFAS are not intentionally used in or added to microwave popcorn bags; rather, if found they are incidental. PFAS are found in almost every place in our world today including forests and polar bears.