In 1961, a DuPont toxicologist warned colleagues that exposure to their company's increasingly popular Teflon chemicals enlarged the livers of rats and rabbits. Studies over the following decades found no safe level of exposure in animals and determined that humans, too, got sick when exposed to the chemicals -- which were also seen to build up in the body and resist breakdown in the environment.
Nonstick, it turned out, tends to stick around.
By the end of 2015, some of these most notorious polyfluoroalkyl and perfluoroalkyl substances, or PFASs, will be fully phased out of use in the U.S. But emerging in their place, warn environmental health experts, are another group of PFASs that share many of the same concerning characteristics.
"We know these substitutes are equally persistent. They don't break down for geologic time," said Arlene Blum, a chemist at the University of California, Berkeley, and the executive director of the nonprofit Green Science Policy Institute.
On Friday, the journal Environmental Health Perspectives published a document known as the Madrid Statement, signed by more than 200 scientists from 38 countries. The statement highlights the potential harm of both old and new PFAS chemicals. You may know them best as the stuff that protects your carpet from stains, keeps your food from sticking to packaging or pans, repels rain from your coat and prevents mascara from running down your cheeks. If you got a pastry with your coffee this morning, a PFAS substance probably even lined the waxy paper it was served on.
"It's a very serious decision to make chemicals that last that long, and putting them into consumer products with high levels of human exposure is a worrisome thing," said Blum, who was also the lead author on the statement.
In an editorial accompanying the statement, Linda Birnbaum, head of the national toxicology program for the Department of Health and Human Services, and Philippe Grandjean, chair of environmental medicine at the University of Southern Denmark, cite the common industry practice of replacing phased-out chemicals with structurally similar ones, such as the recent swap of bisphenol S for bisphenol A. Other experts have pinned this pattern -- what Blum has previously called "toxic whack-a-mole" -- on the nation's outdated toxic chemical legislation, which allows chemicals to remain innocent until proven guilty.
"Companies can currently produce other chemicals without a good idea of their impact on health and the environment," said Alex Stone, a senior chemist with the Washington State Department of Ecology, who signed the Madrid Statement.
The scientists are calling for cooperation around the world to limit production of PFASs and to identify safer alternatives. Industry groups, meanwhile, continue to assert the safety of the newer versions of the chemicals. The replacements carry shorter chains of fluorinated carbon atoms, which experts generally agree lowers the chemicals' toxicity and helps the body excrete them faster.
"There is substantial scientific data supporting the conclusion that short-chain PFASs are not expected to pose a significant risk," wrote Jessica Bowman, executive director of the FluoroCouncil, an arm of the industry group American Chemistry Council, in an emailed statement to The Huffington Post.
Bowman published a counterpoint column in Environmental Health Perspectives on Friday, emphasizing that the unique chemicals are "essential" to "things we take for granted," including products that reduce greenhouse gas emissions in vehicles and coat surgical gowns with a shield against fluid-borne pathogens.
"We don't believe the Madrid statement reflects a true consideration of the available data on alternatives to long-chain [PFASs]," she told HuffPost.
Still, critics contend that not enough information exists to be sure the substitute chemicals are substantially safer than the older versions. "Manufacturers said [long-chained PFASs] were fine for a number of decades," said Blum.
The Madrid Statement cites data that links exposures to PFASs with certain cancers, delayed puberty, decreased fertility, reduced immune response in children and elevated cholesterol, among other health problems. A Danish study published in April adds to the concerns, linking blood levels of PFASs, including the new short-chain versions, with up to a sixteenfold increase in the risk of miscarriage.
When HuffPost asked exactly when it became clear that long-chain PFASs previously used in Teflon and other products were "hazardous to human health," Bowman said only that member companies had started working with the Environmental Protection Agency and other regulators to phase them out "a decade ago."
A decade ago, in 2005, the EPA assessed a $16.5 million fine, its largest ever, to DuPont, saying the company had withheld decades of information concerning the hazardous health effects of PFASs. That's according to a helpful reminder from the nonprofit Environmental Working Group in a separate report also published on Friday. They note that internal documents revealed DuPont had long known the chemicals "caused cancer, had poisoned drinking water in the mid-Ohio River Valley and polluted the blood of people and animals worldwide."
"Even when the EPA manages to punish a company, it's not big enough a deterrent. A couple years' more production easily eclipsed the amount of their fine," said Bill Walker, co-author of the group's report, which was accompanied by a consumer guide for avoiding potentially dangerous PFASs. The group recommends bypassing nonstick pans in favor of stainless steel or cast iron, for example, and popping corn the old-fashioned way -- on the stovetop.
DuPont spokeswoman Janet Smith said in an email that the group's report contained "a number of inaccurate and misleading comments." When asked to specify the inaccuracies, Smith told HuffPost that she was "not able to discuss" because of "active litigation."
Patagonia is among the companies currently phasing out use of long-chain PFASs. But rather than simply embracing their short-chain cousins, spokesman Adam Fetcher suggested that his company is "working really hard to find an alternative" to fluorinated chemicals. He highlighted Patagonia's recent investment in Beyond Surface Technologies, a Swiss startup that's developing plant-based replacement chemicals. "We see a huge amount of potential," said Fetcher.
Stone even pointed to the potential use of biomimicry to offer surface protection without the use of chemicals. "Certain designs in leaves actually help water bead up and run off," he said.
In the end, none of the alternatives may end up quite as effective as today's synthetics. But, as Blum noted, that might be good enough, at least in some cases.
"If you're going to climb Mount Everest, then maybe you need that degree of water repellency," said Blum, who was the first American woman to attempt to ascend the mountain. "But do you need it to go to the beach?"