McDonald's, Burger King, and other fast-food packaging contains toxic 'forever chemicals,'

(Yahoo News) - A type of toxic chemical that has been linked to cancer has been found in some packaging at fast-food giants like McDonald's and Burger King, as well as trendy salad chains such as Sweetgreen and Cava.

McDonald's, Burger King, and other fast-food packaging contains toxic 'forever chemicals,'

A study released by environmental advocacy groups Ecology Center, the Mind the Store campaign, and Toxic-Free Future on Thursday involved testing 38 food packaging samples across six chains for PFAS, or per- and polyfluoroalkyl substances. Nearly half of the samples tested positive for fluorine levels that indicated the packaging contained PFAS. 

PFAS are a category of chemical that have been linked to cancer, liver damage, thyroid disease, and developmental issues. Most people are exposed to PFAS by consuming contaminated food or beverages. As a result, PFAS can be found in the bloodstream of 99% of Americans. 

The study released on Thursday found that fry bags at Burger King, McDonald's, and Wendy's likely contained PFAS. McDonald's cardboard Big Mac containers were also likely treated with PFAS, as was one of the samples taken from a Burger King Whopper wrapper. 

All the bowls at Cava, Freshii, and Sweetgreen were found to likely contain PFAS, according to the study. The Counter reported in 2019 that many of these "compostable" bowls used by fast-casual chains — which were positioned as an eco-friendly alternative to plastic — contain PFAS. 

In all, nearly half of the 38 packaging samples tested across the six chains tested above the fluorine level of 100 ppm, which the environmental advocacy groups use to screen for PFAS. Major compostability certifiers do not certify new items as compostable if they contain more than 100 ppm total fluorine.

There has been a push for new legislation and corporate policies to end the use of PFAS. 

"PFAS can linger in water and air for thousands of years, so consuming or inhaling them means they could stay in the body for life — hence their nickname, 'forever chemicals,'" reports Business Insider's Aria Bendix.

Last week, the US Food and Drug Administration announced it had reached a voluntary agreement with three major producers of food packaging to phase out the use of PFAS. 

"This action follows new analyses of data that raised questions about potential human health risks from chronic dietary exposure – findings that warrant further study," the FDA said in a statement. "This phase-out balances uncertainty about the potential for public health risks with minimizing potential market disruptions to food packaging supply chains during the COVID-19 public health emergency." 

Backlash against PFAS, lead by environmental groups, has also sparked action among major chains. 

CNN reports that Cava, Sweetgreen, and Freshii have announced plans to eliminate PFAS from food packaging in the coming months. Cava told Business Insider that it plans to eliminate PFAS from food packaging by mid-2021. Sweetgreen said in a statement to Business Insider that it plans to roll out PFAS-free compostable bowls by the end of the year. 

"We originally introduced compostable containers to make a positive impact on the food ecosystem, however, given the concerns around PFAS, we started working with new and existing suppliers as well as an independent safety expert to find a more sustainable and compostable solution," Sweetgreen said in a statement. 

"We are looking forward to extending our safe ingredients policy to include the removal of the short-term PFAS recently identified by the FDA," a Burger King representative said in a statement to Business Insider. "We will work with our suppliers to remove them from all packaging by or, where feasible, earlier than the three years recommended by the FDA." 

McDonald's said it is also taking action, noting in a statement that "the safety and well-being of our communities is our top priority."

"We've eliminated significant subset classes of PFASs from McDonald's food packaging across the world," McDonald's said in a statement. "We know there is more progress to be made across the industry and we are exploring opportunities with our supplier partners to go further."