The Environmental Protection Agency has moved to reclassify two commonly used chemicals as “hazardous substances,” after a growing body of scientific research linked them to cancer and other health problems. On Friday, the EPA said its move to reclassify PFAS under the federal Superfund law could accelerate cleanup efforts at hundreds of toxic sites across the U.S. PFAS are often called “forever chemicals,” because they can take centuries to break down in the environment. They’re used in everything from food packaging and cookware to cosmetics, fabrics and firefighting foam. In humans, PFAS have been linked to a host of dangerous health effects, including liver damage, decreased fertility, asthma, thyroid disease, low infant birth weight and cancer.