The risky chemicals that keep cooking grease from leaking out of fast-food containers are widespread, according to a peer-reviewed study released Wednesday.

Researchers said they detected fluorine in nearly half the 400 container samples from 27 fast-food chains, including the four largest in the U.S., McDonald’s Corp., Starbucks Corp., Chipotle Mexican Grill Inc. and Yum! Brands Inc. That’s an indication that potentially dangerous chemicals, called PFAS, were present in wrappers for popular items like burgers, burritos and pastries, the authors said.

The study found desserts, bread and Tex-Mex foods were most often exposed, and that at three restaurants, Jimmy John’s, Quiznos and Taco Time, 100 percent of samples tested positive. At McDonald’s, 19 percent did.

The U.S. Food and Drug Administration has approved about 20 of the 3,000 estimated PFAS for use in food packaging. But what’s troubling scientists is a lack of information on whether the PFAS, also called PFCs, are different enough from chemical cousins, once used in products like Teflon and Scotchguard, phased out by manufacturers such as DuPont Co., its spinoff Chemours Co., Daikin Industries Ltd., and Solvay SA. Unexpectedly, PFOA, one of the older generation of substances, was found in six of 20 packaging samples in a more in-depth test conducted for the study.

Wax Paper

“We have things we do know are not problematic,” such as wax paper, said Linda Birnbaum, director of National Institute of Environmental Health Sciences, part of the National Institutes of Health. “Why not use them?” Birnbaum said that the industry adopted new non-stick and grease-proof coatings before gathering enough facts, and that the data on health risks are limited.

Six ailments, including testicular cancer, ulcerative colitis and high cholesterol, have been linked to the older generation of compounds, and the study says there isn’t enough evidence that the new generation doesn’t have similar risks.

Chemours and Solvay have said in online statements that the new generation of chemicals comply with regulatory guidelines. DuPont declined to comment, referring the issue to Chemours. A Chemours spokesman declined to comment. Daikin and Solvay didn’t respond to requests for comment.

Lynn Dyer, president of the industry group Foodservice Packaging Institute, said that new fluorine-free products have been introduced since the study was conducted.

“Food-service-packaging products go through rigorous testing to ensure that they meet stringent U.S. Food and Drug Administration regulations, providing the safe delivery of foods and beverages to consumers,” Dyer said.

Terri Hickey, a McDonald’s spokeswoman, denied the chain’s packaging contained PFAS. “Our packaging is safe for its intended use and contains materials that meet FDA standards,” she said in an e-mail.

FDA Requirements

Chris Arnold, a spokesman for Chipotle, said the study “seems to suggest that there is room for improvement.” While Chipotle’s packaging complies with FDA requirements, the company is “in the process of obtaining documentation from our suppliers that the packaging materials they supply to Chipotle are PFC-free,” and in light of the study, will continue to make that a priority, Arnold said.

“We take food safety very seriously,” Quiznos Chief Executive Officer Susan Lintonsmith said in an e-mail. “We were just made aware of this study and we are working with our suppliers to fully understand the situation.”

A Starbucks spokeswoman declined to comment. Spokesmen for Jimmy John’s and Taco Time didn’t respond to requests for comment.

The study, published in Environmental Science & Technology Letters, didn’t check for PFAS in the food, but cited other studies that say the chemicals migrate there, particularly when food is hot.

Trade Secrets

The researchers also didn’t try to detect exact compounds, which are often guarded as trade secrets, but used a quick and inexpensive method to measure fluorine. Its presence was a signal that one of the thousands of chemicals known as a PFAS was present, they said.

Birnbaum called the study’s science “solid” and said more testing should be done to check for specific compounds. The presence of PFOA could be due to imported products, she said.

PFAS have been used in food packaging since the 1960s, according to the FDA. The older “long-chain” chemicals like PFOA, also known as C-8 for its eight carbon-fluorine bonds, “persist in the environment and can have toxic effects on humans and animals,” the agency said of its decision to ban them in food packaging as of 2011. Another long-chain PFAS, PFOS, was once used in 3M Co.’s Scotchguard.

The 20 compounds the FDA has approved for such use are a new generation of chemicals – often referred to as short-chain, since they contain fewer than 8 carbon-fluorine bonds.

FDA spokeswoman Megan McSeveney said the agency has “carefully reviewed the available science” on the short-chain compounds and hasn’t identified any safety concerns. The agency continues to review emerging science, she said.
But groups such as the Green Science Policy Institute that participated in the study said there’s not enough research to show the new chemicals are safe.

“We should question putting any fluorinated materials into contact with food,” said Arlene Blum, visiting scholar in University of California-Berkeley’s chemistry department, founder of the institute and one of the study’s authors. “Given the potential for harm, we must ask if the convenience of water and grease resistance is worth risking our health.”