The companies Chemours, DuPont and Corteva announced on Friday they have agreed to pay more than $1 billion to settle claims that “forever chemicals” contaminated public US water systems.

The family of ubiquitous synthetic chemicals – per- and polyfluoroalkyl substances, also known as PFAS – linger in the environment and the human body, where they can cause serious health problems, and are found in everyday products including fast-food wrappers, makeup and carpeting.