Toxic PFAS "forever chemicals" are widely added to pesticides, and are increasingly used in the products in recent years, new research finds, a practice that creates a health threat by spreading the dangerous compounds directly into the US's food and water supply. The analysis of active and inert ingredients that the Environmental Protection Agency (EPA) has approved for use in pesticides proves recent agency claims that the chemicals aren't used in pesticides are false. The researchers also obtained documents that suggest the EPA hid some findings that show PFAS in pesticides. About 14% of all active ingredients in the country's pesticides are PFAS, a figure that has doubled to more than 30% ... during the last 10 years. PFAS are a class of about 15,000 compounds typically used to make products that resist water, stains and heat. They are called "forever chemicals" because they do not naturally break down and accumulate, and are linked to cancer, kidney disease, liver problems, immune disorders, birth defects and other serious health problems. PFAS are added to a range of pesticides, including those used on crops, to kill mosquitoes, or to kill fleas. About two years ago, an EPA research fellow identified PFOS in pesticides and raised the alarm. In a Freedom of Information Act request that was part of the new study, researchers found documents showing the EPA had in fact found PFOS in pesticides but omitted those findings from the final study.