All PFAS consist of a chain of carbon atoms to which fluorine atoms have been added. However, the bond between a carbon and a fluorine atom is extremely strong, meaning that PFAS degrade very little naturally and are therefore very persistent in the environment (hence their name ‘forever substances’).
Given their widespread use by industry since the 1950s, PFAS accumulate everywhere in the environment, particularly in the water and in the soil, but also in the human body.