New Study Warns of Potential Chemical Exposure from Black Kitchen Utensils

Banned toxic flame retardants can make their way into household items, including cooking utensils and food containers, new research found. 

Researchers tested products made from black plastic, which largely enters the recycling stream after first serving as protective parts for electronics, such as the enclosures on the back of televisions. 

These plastics are often treated with flame retardants when used in electronics. But even after the items are recycled, the chemicals—which have been linked with a number of negative health impacts—can remain in the materials in high concentrations, according to the study.

“This study highlights the lack of chemical regulation on what is entering our recycling system,” the study’s lead author, Megan Liu, science and policy manager at Toxic-Free Future, told Health.

For the study, published this month in the journal Chemosphere, Liu and two other researchers, including an environmental chemist, tested 203 household items made from black plastic for various chemicals. The products included takeout containers, sushi trays, fast food trays, children’s toys, and kitchen utensils such as spatulas.

Each item was first screened for bromine, a chemical found in some flame retardants. If an item contained more than 50 parts per million of bromine, the team then tested the product for brominated flame retardants and organophosphate flame retardants. These are commonly used in electronics and have been linked to health effects, including cancer and endocrine disruption.

Researchers found that 85% of the products the team analyzed contained flame retardant chemicals, while 65% contained a mixture of both classes of flame retardants. The highest amounts of flame retardants were found in a sushi tray, spatula, and pirate-themed beaded necklace meant for dress-up.

The necklace contained 22,800 milligrams per kilogram of flame retardant, which Liu said equaled about 2.3% of the entire product’s weight.

“We know flame retardants leach out and that kids put toys in their mouths,” Liu said. “That particular product contained four different types of flame retardants.”

The necklace and other products used to store or prepare food contained decabromodiphenyl ether (decaBDE), a type of brominated flame retardant that the Environmental Protection Agency banned in 2021 from being manufactured, processed, or distributed. The agency started phasing out the class of chemicals it belongs to—PBDEs—in 2009. At that time, the agency noted that “polybrominated diphenyl ethers (PBDEs) are persistent, bioaccumulative, and toxic to both humans and the environment.”

A study published earlier this year in JAMA Network Open found that people with the highest levels of PBDEs in their blood were 300% more likely to get cancer. 

The finding that decaBDE is still found in household items following the ban illustrates a failure of manufacturers to understand where their plastic is coming from and of the recycling system, which does not seem to be separating out plastic treated with banned chemicals, Liu said. 

In products containing decaBDE, levels ranged from 5 to 1,200 times greater than the European Union’s limit of 10 parts per million. Liu estimated that people’s average risk of exposure to decaBDE could be as high as nearly 35 parts per million every day.

“It’s a wake-up call,” Linda S. Birnbaum, PhD, a scholar in residence at Duke University’s Nicholas School of the Environment, told Health.

Jaimie Ross, PhD, an assistant professor of neuroscience at the University of Rhode Island, whose research includes microplastics’ impact on human health, said she was surprised by the findings. 

“I was aware of flame retardants and that they were trying to phase them out of children’s clothing,” she told Health. “But I wasn’t aware they were bypassing restrictions and were incorporated into household products that they obviously do not need to be in, that recycling was not as strict as it should be to keep out these flame retardants.”

The health risk different flame retardants pose depends on their type, but research has shown that the chemicals bioaccumulate, meaning they build up in the body. 

“Some of the greatest concerns are cancer, neurodevelopmental effects, and reproductive and developmental effects,” said Birnbaum, also the former director of the National Institute of Environmental Health Sciences at the National Institutes of Health and the National Toxicology Program at the Department of Health and Human Services.

Although other flame retardants have replaced decaBDE in electronics, “those have still been linked to neurotoxicity, cancer, reproductive harm,” Ross said. “These are clearly not things we want to come into contact with.”

Ultimately, it’s up to manufacturers and those in charge of recycling systems to drive systemic change that keeps harmful chemicals out of household items, especially those meant for children and those used in food, Ross said. Because plastic has become so ubiquitous, it can be difficult for the average person to avoid both plastic and the chemicals it harbors.

“This study looked at certain flame retardants, not all, and there are many other chemicals of concern which are present in plastics,” Birnbaum told Health. “I would stop using black plastic used with food.”

This includes cooking utensils. If you do receive takeout in plastic containers, particularly those made from black plastic, Ross said never to reheat the food in those containers and to try to store leftovers in a metal or glass container instead.

“Look around your home, do a scan, think about how you go about your daily life, how do you make your food, what kind of containers are you storing your food in, how are you making your coffee and tea, what are you drinking your items out of?” Ross said. “If you have anything plastic, hand wash it, do not put it in the dishwasher.”

When it comes to black plastic items outside the kitchen, she said what needs to go is nuanced. For example, if a decoration that hangs on the wall is made from black plastic, it’s probably no big deal. But anything that a child plays with or that’s used for food warrants more caution.

“Not everything will be perfect. When I travel, I bring food in a hard plastic container that I’ve had forever. I don’t heat it up, but it’s not metal,” she said. “Try not to add to the problem by using single-use plastics.”