FDA raises concerns about PFAS in food

The US Food and Drug Administration is reminding manufacturers that only certain processes are allowed for fluorinating polyethylene containers used to store food. The warning comes following reports earlier this year of toxic per- and polyfluoroalkyl substances (PFAS) migrating into pesticides stored in fluorinated high-density polyethylene containers.

In an Aug. 5 letter to industry, the FDA clarifies that fluorinated polyethylene containers used for food can only be made using fluorine gas in the presence of nitrogen to modify the surface of a molded container. Fluorination in the presence of water, oxygen, or inert gases other than nitrogen is not allowed because such processes can lead to the formation of toxic PFAS that can migrate into food, the agency says. Fluorination of polyethylene food containers during the molding process is also prohibited.

The FDA claims that it sent the letter out of an abundance of caution, not because it is aware of any unauthorized fluorinated polyethylene containers being used to store food. “It is important to note that there is no evidence of unlawful manufacturing processes being used for food containers,” Susan Mayne, director of the FDA’s Center for Food Safety and Applied Nutrition, says in a statement. “We are encouraging manufacturers and distributors to consult with us regarding the regulatory status of any manufacturing processes used to produce fluorinated polyethylene containers for use in contact with food,” she says.

Environmental groups want the FDA to investigate companies that make fluorinated plastic containers for storing food and cosmetics to ensure that their processes are authorized. They are also pushing the agency to reassess the safety of fluorinated polyethylene containers for such uses, even if they comply with the law.

The FDA approved the process of fluorinating polyethylene food containers in 1983. At the time, the agency determined that the process made no significant quantities of PFAS. But what was considered significant then is different from what is considered significant now, says Tom Neltner, chemicals policy director at the advocacy group Environmental Defense Fund. “We now know that PFAS is much more dangerous” than people believed nearly 4 decades ago, he says.

In an Aug. 9 blog post, Neltner identifies three manufacturers that are using processes to fluorinate polyethylene that are unauthorized for food containers. It is unclear what those containers are used for, but one of the companies lists flavors and fragrances as a potential market.

Fluorination of polyethylene containers helps keep food and cosmetics, as well as cleaning products, agricultural chemicals, petroleum-based fluids, and other liquids from spoiling by providing a barrier to keep out oxygen and moisture. With respect to food, these containers could be used to hold vegetable oils, flavoring agents, liquid dairy products, or nearly any liquid “you are worried about going bad,” Neltner says.