What’s in your food packaging? Study finds thousands of chemicals, major unknowns

Parents can check the sugar in their kids’ yogurt, the sodium in their snacks and every ingredient in a box of cereal.

But figuring out what chemicals are in the packaging touching that food can be far more difficult.

A new peer-reviewed study identified more than 1,200 chemicals used in or detected in food-contact materials that researchers say have known human health hazards, highlighting what scientists describe as significant gaps in understanding the thousands of chemicals that can come into contact with food.

Researchers analyzed 15,159 known food-contact chemicals and identified 1,222 with established hazard classifications, including chemicals linked to cancer, reproductive toxicity, endocrine disruption or damage to specific organs after repeated exposure. The study was published this month in the journal Environmental Science & Technology.

That does not mean those chemicals are necessarily present in every package — or that using a product containing one will make someone sick. Risk depends on factors including whether a chemical migrates into food, how much a person is exposed to and the toxicity of the chemical.

But researchers say there are substantial gaps in what is known about many of the chemicals associated with materials that touch food.

At least 2,160 chemicals are known to migrate from food-contact materials into food, according to the study. Researchers placed 94 chemicals in their highest-priority tier because there is evidence they migrate from food-contact materials and have also been detected in people through biomonitoring programs.

‘One more thing that I need to worry about’

For Raleigh mom and content creator Isha Kalra, known as “The Very Exhausted Mommy” on Instagram, the findings add another consideration to an already long list.

“Every time I hear about a new study that comes out, I'm like, ‘Oh, my gosh, that's one more thing that I need to worry about as a parent,’” Kalra said.

Parents are already thinking about whether their children are getting enough protein, fruits and vegetables or eating too much processed food, she said. Now, she said, there is another question: What is that food packaged in?

“That's just adding on to the mental load,” Kalra said.

Kalra said she sometimes chooses products packaged in glass rather than plastic, but acknowledged packaging is rarely the first consideration during a grocery run.

Avoiding plastic altogether, she said, feels nearly impossible.

“Pretty much everything is wrapped in plastic,” Kalra said, pointing to everything from yogurt and cheese to the plastic bag inside a cardboard cereal box. Alternatives can also be more expensive and harder to find.

Why chemicals can move from packaging into food

Dr. Nishad Jayasundara, an assistant professor at Duke University's Nicholas School of the Environment, studies how environmental exposures affect human and animal health.

He said plastics are not simply one material. Manufacturers use numerous chemical additives to give plastics properties such as flexibility, durability and heat resistance.

Researchers are increasingly studying what happens to those additives during real-world use.

“We heat up our food, we put acidic food into it, we put food that are oily,” Jayasundara said. Those different conditions, he said, can change how chemicals in a material leach into food.

Heat is one factor that can increase migration, Jayasundara said. Acidity, ultraviolet light and the fat content of food can also matter. Certain compounds are attracted to fat, making oily or fatty foods particularly relevant when scientists study chemical migration from packaging.

Jayasundara pointed to hot food placed directly into plastic as one exposure researchers are interested in studying.

Duke researchers are part of a National Science Foundation-funded project examining plastic additives and their potential health effects. One of the questions researchers are trying to answer is how long additives remain in plastics, how readily they leach out and how much can ultimately reach food or the environment.

Why you can't just check the label

The challenge for consumers is that packaging generally does not come with anything resembling the ingredient list printed on food.

“Unfortunately, we don't do a really good job in identifying what's in the packaging,” Jayasundara said. “We do a great job, or a better job, in saying what's in the food that you're about to buy, but we don't really know what went into the package.”

He called that a “huge policy gap,” particularly because the same package may behave differently depending on whether it is heated, exposed to sunlight or used with acidic foods.

Kalra said even more disclosure would have limited value if shoppers needed a chemistry degree to understand it.

“When you're standing in that grocery shop aisle, you don't have the time,” she said. “And God forbid if you have kids with you — no.”

She said information about packaging chemicals would need to be presented in language ordinary consumers could understand.

How food-contact chemicals are regulated

The U.S. Food and Drug Administration says food-contact substances that qualify as food additives must be authorized for their intended use before being marketed. The agency says its food-contact notification process considers both toxicology and how much of a substance is expected to migrate into food under its intended conditions of use.

Food-contact substances can have different regulatory pathways depending on the substance and use, including FDA regulations, food-contact notifications, prior sanctions, threshold-of-regulation exemptions or meeting criteria for “generally recognized as safe” status.

The FDA is also continuing to reassess some chemicals already authorized for food-contact uses. In May, the agency released an evaluation supporting grouping four currently authorized phthalates together for a future cumulative risk assessment.

The authors of the new study argue that evaluating chemicals one at a time can be too slow and can lead to what scientists call “regrettable substitutions” — replacing a restricted chemical with a structurally similar chemical that may ultimately pose similar concerns.

They cite bisphenol A, or BPA, and its replacement in some applications with bisphenol S, or BPS, as an example. The researchers identified 38 priority groups of structurally related food-contact chemicals, including PFAS and ortho-phthalates.

Jayasundara said grouping chemicals either by their chemical structure or biological effects could help scientists and regulators keep up with the pace at which new chemicals enter use.

“The rate at which chemicals are being produced and released into the environment is way faster than our ability as scientists to keep track of what those chemicals do,” he said.

What can consumers do?

Jayasundara said consumers who want to reduce exposure can avoid heating food in plastic when possible, particularly hot or fatty foods, and use materials such as glass or stainless steel for food storage.

He also recommended replacing reusable plastic containers when they become visibly worn or cloudy rather than continuing to reuse them indefinitely.

But both Jayasundara and Kalra said consumers can only do so much.

Jayasundara said better policies could reduce the burden on shoppers to understand the chemical composition of every package they buy. Even basic information indicating that a package contains chemicals with known endocrine-disrupting properties, for example, could give consumers more ability to make their own decisions.

Kalra takes a similar approach at home: make better choices when they're practical, but recognize that eliminating every potential exposure is unrealistic.

“I want to see more evidence. I want to see more resources before I make a decision,” she said. “We try to make better choices every day.”

And when it comes to everything parents are already worrying about?

Packaging is “definitely on the list,” Kalra said. “But it's definitely not the first item.”