The term "forever chemicals" typically refers to a group of chemicals known as per- and polyfluoroalkyl substances (PFAS). PFAS encompass a large number of individual compounds with similar chemical structures but varying chain lengths. Some commonly known PFAS include: 1. Perfluorooctanoic acid (PFOA): PFOA has been widely used in the production of non-stick coatings, such as Teflon, as well as in stain-resistant fabrics and firefighting foams. It has been associated with potential health risks and has been phased out by many manufacturers. 2. Perfluorooctanesulfonic acid (PFOS): Similar to PFOA, PFOS has been used in various industrial and consumer products, including firefighting foams, waterproof textiles, and cleaning agents. It has been found to persist in the environment and has been phased out in many countries. 3. Perfluorohexane sulfonic acid (PFHxS): PFHxS is another PFAS compound that has been used in industrial applications and firefighting foams. It is known for its persistence and bioaccumulation potential. 4. GenX chemicals: GenX refers to a group of PFAS compounds that have been used as alternatives to PFOA. They have similar properties and applications and have been found to raise environmental and health concerns.