At first, Tomas Monarrez didn't notice the labels when he went shopping for pots and pans. 'Completely toxin free!' said a big green message on a line of nonstick frying pans in the cookware aisle at a store in the nation's capital. 'No PFOA!' boasted the label on a 12-piece kitchen set. 'Will never release any toxic fumes,' another label promised. 'Oh, wow,' Monarrez, an economist at a think tank, said, when asked if he had ever heard of the toxic chemicals that manufacturers were declaring their products free of. 'I didn't know anything. Should I buy these?' Monarrez asked. 'So all these are bad? Federal regulators are sorting out how to handle health risks from a group of widely used nonstick and stain-resistant compounds. But even reading labels may not be enough to guide consumers who want to limit their exposure to the manmade industrial material, known as perfluoroalkyl and polyfluoroalkyl substances, or PFAS. Scientists say there are many steps people can take to minimize their contact with the compounds, which federal toxicologists say show links to health problems. Some changes are simple, such as checking on the safety of your drinking water or buying different pots and pans. Others require spending and lifestyle changes — for example, passing up fast food or other takeout because the containers the food may be packaged in. For those concerned about exposure, there's one critical thing to know about PFAS compounds: 'They're everywhere,' Linda Birnbaum, head of the National Institute for Environmental Health Sciences, told a recent gathering of her agency's advisory council. 'The carpets and the chairs and maybe the clothes you're wearing,' Birnbaum said. She noted she used to love the ritual of spraying Scotchgard on newly bought tablecloths. No more, she made clear. There are thousands of different versions of the compounds, including PFOA and another early version, both now phased out of production in the U.S. PFAS are used in products including nonstick cookware, but also in stain- and steam-resistant bags for microwave popcorn and many other food containers and packaging, shaving cream, dental floss, stain protection for fabrics and rugs and outdoor garb — for starters. Federal studies of people heavily exposed to the compounds have found links between high blood levels of older kinds of PFAS and a range of health problems, including liver issues, low birth weights, and testicular and kidney cancer. High levels also have been found in many drinking water systems. Military installations that use PFAS-laden firefighting foam and businesses that work with PFAS are two big sources of water contamination. It's probably impossible to avoid all exposures, says Leonardo Trasande, a children's environmental health specialist and vice chair for research at New York University's pediatrics department, and a PFAS expert. But there are 'safe and simple steps to limit exposure based on what we know,' Trasande says. Trasande himself recommends two precautions. One is shunning nonstick cookware in favor of cast iron or stainless steel, Trasande said. That's despite statements from industry and manufacturers that newer forms of PFAS in nonstick cookware are safe. The other is eschewing food packaging as much as possible. In practice, that can require changing habits — cutting your consumption of takeout and packaged food, and committing to cooking more at home, from scratch. 'Literature does suggest that diet is a major route of exposure,' Trasande noted. People also can contact their local water utility to find out if their water system is one of those testing with higher levels of PFAS, Environmental Protection Agency spokeswoman Andrea Drinkard said. Eating certified organic food can guard against PFAS exposure from fields treated with treated human sewage sludge because federal rules prohibit use of the sludge on organically raised crops and livestock, environmental groups say. Older forms of the compounds are known to build up in people's bodies for years. And the chemical bonds holding PFAS compounds together are among the toughest going, so they are expected to take thousands of years to degrade. There's no across the board consensus on whether newer versions of the thousands of kinds of PFAS are safe. Industry says they are and that there's no reason to swear off all nonstick cookware and PFAS-treated food packaging. 'Consumers should have confidence in the safety of products manufactured with today's PFAS because they have been reviewed by regulators globally and found to meet relevant standards that are protective of health and the environment,' Jessica Bowman, executive director of the FluoroCouncil industry trade group, said in an email. 'Studies show that the newer PFAS do not present significant health concerns — they're not carcinogenic and not endocrine disruptors.' Several nonindustry researchers dispute that, and the Food and Drug Administration noted last month studies showing that that newer forms of the nonstick, grease- and water-repelling compounds may also be a health concern.