Toxic wrappers: Researchers have detected fluorine in US fast-food packaging. Picture: ISTOCK
Toxic wrappers: Researchers have detected fluorine in US fast-food packaging. Picture: ISTOCK

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

Researchers say they had detected fluorine in nearly half the 400 container samples from 27 fast-food chains, including the four largest in the US — McDonald’s, Starbucks, Chipotle Mexican Grill and Yum! Brands. That’s an indication that potentially dangerous chemicals, called PFASs, are present in wrappers for popular items such as burgers, burritos and pastries, the authors say.

The study found desserts, bread and Tex-Mex foods were most often exposed and, at some restaurants, 100% of samples tested positive.

At McDonald’s, 19% of samples contained the chemicals.

The US Food and Drug Administration (FDA) has approved about 20 of the 3,000 estimated PFASs for use in food packaging. But scientists are troubled about the lack of information on whether the PFASs, also called PFCs, are different enough from their chemical cousins — once used in products such as Teflon and Scotchguard — that had been phased out by manufacturers such as DuPont, its spinoff Chemours, Daikin Industries and Solvay.

Unexpectedly, PFOA, one of the older generation of substances, was found in six of 20 packaging samples in a more in-depth test that had been conducted for the study.

"We have things we do know are not problematic," such as wax paper, says Linda Birnbaum, director of National Institute of Environmental Health Sciences, part of the National Institutes of Health.

"Why not use them?"

Birnbaum says that the packaging industry adopted new nonstick and grease-proof coatings before gathering enough facts about them, 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 is not enough evidence that the new generation does not face 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 instead.

A Chemours spokesman declined to comment. Solvay also declined to comment.

Daikin says it supports a statement by FluoroCouncil, an industry group that says attention to the new group of chemicals is "unfounded and unnecessary". There are now potentially dangerous chemicals "that have been carefully reviewed and approved for use in coating food-contact papers to keep grease, oil and moisture from seeping through the packaging", the FluoroCouncil says.

Lynn Dyer, president of the US industry group Foodservice Packaging Institute, says 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 US Food and Drug Administration regulations, providing the safe delivery of foods and beverages to consumers," Dyer says.

Terri Hickey, a McDonald’s spokeswoman, denies that the chain’s packaging contains PFAS. "Our packaging is safe for its intended use and contains materials that meet FDA standards," she says.

Chris Arnold, a spokesman for Chipotle, says 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 that they supply to Chipotle are PFC-free", and in light of the study, will continue to make that a priority, Arnold says.

A Starbucks spokeswoman declined to comment.

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

The researchers also did not 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 say.

Birnbaum calls the study’s science "solid" and says more testing should be done to check for specific compounds. The presence of PFOA could be due to imported products, she adds.

PFASs have been used in food packaging since the 1960s. The older "long-chain" chemicals such as 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 FDA said when it decided 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 eight carbon-fluorine bonds.

FDA spokeswoman Megan McSeveney says the agency has "carefully reviewed the available science" on the short-chain compounds and has not identified any safety concerns. The agency continues to review emerging science, she adds.

But groups such as the Green Science Policy Institute that participated in the study say there is not enough research to show that the new chemicals are safe.

"We should question putting any fluorinated materials into contact with food," says Arlene Blum, visiting scholar at the 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."


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