Chemicals once commonly found in a range of products, including pizza boxes and microwave popcorn bags, are no longer being used in food packaging in the United States, the Food and Drug Administration said Wednesday.

Eliminating the grease-proofing substances ends a yearslong campaign by the agency to phase out per- and polyfluoroalkyl substances, or PFAS, toxic chemicals that may be linked to serious health problems, including cancer, birth defects and immune system suppression.

PFAS create a barrier that prevents oils, greases and water from seeping through food packaging, keeping the food dry and fresh.

They were once unavoidable in people’s day-to-day lives, being used in everything from fast-food wrappers to pet food bags.

Following extensive research over the last decade that found the chemicals can leach into food and may be associated with serious health problems in humans, food manufacturers gradually began to phase them out. In 2020, the FDA said it received commitments from the remaining food manufacturers to remove PFAS from their products voluntarily over the next few years.

“The completion of the voluntary market phase-out of these substances used on food packaging paper and paperboard, eliminates the primary source of dietary exposure to PFAS from authorized food contact uses,” the FDA said in the release Wednesday.

It’s been a drawn-out process; the possible health risks of PFAS have been known — and debated — for years.

In 2015, 200 scientists signed the Madrid Statement, urging manufacturers to find safer alternatives to PFAS, noting that the chemicals may harm humans and the environment.

A recent study published in The Lancet’s eBioMedicine found that PFAS may be associated with an increased risk of thyroid cancer.

According to the Centers for Disease Control and Prevention, PFAS can be found in the blood of people and animals, and some PFAS can build up in people with repeated exposure over time.