By Morgan Hines

Everything about your burrito bowl from Chipotle or your salad from Sweetgreen seems earthy and health-conscious, right down to the packaging.

But harmful chemicals may be lurking in those eco-friendly containers.

A story published last week by the New Food Economy, a non-profit newsroom that investigates food-related issues, reported the “cancer-linked” presence of PFAS, also called “forever chemicals,” in the fiber bowls used at fast casual dining spots and other restaurants including Chipotle, Sweetgreen, Dig Inn and other locations in New York City.

The chemicals are being investigated by scientists and government officials amid concerns over links to cancer, obesity, reproductive health problems, immunotoxicity and other health problems. PFAS have been used in consumer goods since the 1940s, according to the Food and Drug Administration. They’ve also been found in water.

The methodology used in the report has been questioned by the Foodservice Packaging Institute, a trade group that claims the report’s chemical indicators may not always prove accurate. And Chipotle contended its fiber bowls are safe and compliant with Food and Drug Administration rules in a statement to USA TODAY.

But the potential presence of PFAS is worrisome for health and environmental concerns, according to researchers.

Why ‘forever chemicals’ don’t go away

PFAS, per- and polyfluoroalkyl substances, is a family of man-made chemicals that contain carbon-fluorine bonds. The bonds don’t break down easily, which is why PFAS are often referred to as “forever chemicals.”

They have been used in the production of common goods since the 1940s, according to the FDA.

And PFAS are everywhere: Drinking water, food, cookware, paints, water-repellent fabrics, nonstick products, firefighting foams and more.

Because it doesn’t break down, PFAS remain present in our groundwater, soil and in human and animal bloodstreams, the FDA said in a statement.

While there is evidence that PFAS are present in many other areas of our world, people have had a strong reaction to the news about it being a part of packaging, said Caroline Cox, senior scientist at the Center for Environmental Health.

“I think people are often concerned about contaminants in their food – it’s such a direct exposure,” Cox told USA TODAY.

Bowls made out of waste fibers – such as wood waste and sugar cane – are made with compostability in mind. And using waste to create new disposable packaging feels like a better choice than using new plastic, Cox said.

“In order to make those dishes water and grease proof, what they did was add these PFAS chemicals to provide those functions,” Cox said.

And when those bowls break down, after being in contact with food we eat, the chemicals end up in the compost, Cox said.

Lisa Marchewka is vice president of strategy at Evoqua Water Technologies, which sometimes works to remove PFAS from water. She told USA TODAY that the chemicals are even in living organisms that we eat like fish and meat.

There are nearly 5,000 chemicals in the PFAS group. Only a handful have been studied for toxicity, and the results are “very concerning,” said Cox.

According to Marchewka, PFAS tend to move “through the entire ecosystem.” Because such a chemical may not biodegrade, “it works its way through the entire life-cycle of anything it touches,” she said.

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Should I be concerned about these containers?

In its statement to USA TODAY, Chipotle said that it is committed “to using safe and sustainable food packaging and only partner with suppliers who make fluorochemical sciences and food safety a top priority.”

Chipotle’s suppliers operate under FDA guidelines and certify that all raw materials and the finished pulp products meet regulatory standards, the chain said.

Sweetgreen and Dig Inn did not respond to requests for comment from USA TODAY.

Laura Abshire, director of food and sustainability policy at the National Restaurant Association, said that restaurants work with suppliers to ensure all packaging meets those FDA requirements.

“The Food and Drug Administration approves substances for food contact when scientific data demonstrates that substance is safe for its intended use,” Abshire said.

In spite of accordance with FDA regulations, scientists are still worried about health impacts.

“There is research that shows that PFAS chemicals migrate from the dish into the food so that you are likely eating them,” Cox said. She recommends people make an effort to bring their own reusable containers for the restaurant to use.

What does the FDA say?

While there has been growing concern about PFAS, its effects are still under investigation by scientists and the government.

In a June 11 statement, the FDA said it did not detect PFAS in the vast majority of foods tested in a study on foods and food packaging,

“Based on the best available current science, the FDA does not have any indication that these substances are a human health concern, in other words a food safety risk in human food, at the levels found in this limited sampling,” the agency said.

Current evidence suggests accumulation in the human body of some PFAS could cause serious health conditions, according to the FDA. Their team, along with other national and local agencies, will continue to test and research.

The decline of use of PFAS in newer products is helping to stop the accumulation of PFAS in humans in the United States, the FDA said.

The science surrounding the health effects of PFAS is still murky.

“It’s because there’s a lot of data gaps in terms of the information about the toxicity and what amounts are toxic and stuff like that,” Cox said. “It’s hard to know exactly how big of a problem it is.”

The Foodservice Packaging Institute noted in its release that not all PFAS chemicals are the same, and they shouldn’t be treated like they are.

“Therefore, calls to remove the entire class of these beneficial chemicals are unfounded,” the group said.