PFAS are added to food packaging to make paper and cardboard grease-resistant and moisture-proof. A pizza box that holds its shape despite hot cheese. A burger wrapper that does not become translucent with grease. A microwave popcorn bag with a crisp interior lining. All of these rely on PFAS-based coatings. When food sits in contact with PFAS-coated packaging, particularly fatty food at elevated temperature, the PFAS migrate into the food. You eat them.
Why food packaging contains PFAS
Paper and cardboard are naturally permeable to grease and moisture. Without treatment, fast food packaging would fail within minutes of containing a burger or slice of pizza. PFAS produce a durable, grease-resistant surface coating at a fraction of the cost of alternative materials. They are used in sandwich wrappers, pizza boxes, french fry containers, pastry bags, paper plates and microwave popcorn bags. They are also used in some coffee cups and soup containers. Until regulatory pressure began to build around 2015, PFAS use in food contact paper was essentially unregulated in most countries.
What independent testing has found
A 2017 study by the Silent Spring Institute tested 407 fast food packaging items from 27 US restaurant chains and found detectable fluorine in 46% of food contact paper and 20% of paperboard. Items most likely to test positive included tex-mex food wrappers (over 90% positive), dessert and bread wrappers (38-56% positive), and sandwich and burger wrappers. A 2022 follow-up study found PFAS still present in packaging from major chains despite some voluntary commitments. Testing found long-chain PFAS being replaced by short-chain alternatives that remain in the same chemical family with unresolved safety profiles.
How heat accelerates migration
Temperature is the key variable in PFAS migration from packaging into food. A 2020 study in Environmental Science and Technology found that microwave popcorn bags released measurable PFAS into the popcorn during microwaving, with migration proportional to time and temperature. PFAS also migrate from packaging into fatty foods more readily than into dry or water-based foods, because PFAS are lipophilic. A slice of pizza sitting in a box accumulates more PFAS than dry bread in the same box.
Which food chains have committed to PFAS removal
Several US states (California, New York, Washington, Colorado) have passed legislation banning PFAS in food packaging. McDonald's committed to eliminating PFAS from packaging by 2025. Whole Foods eliminated PFAS from its own-brand packaging. Chipotle, Sweetgreen and several other chains have made similar commitments with varying levels of third-party verification. However, restaurant supply chains are complex and independent verification of PFAS removal is limited. The safest approach is to assume PFAS presence until independently verified otherwise.
What to do
Transfer fast food to a plate before eating
Removing food from packaging before eating significantly reduces migration time. Hot chips in a cardboard box for 10 minutes transfer more PFAS than chips immediately tipped onto a plate.
Avoid microwave popcorn bags
Microwave popcorn bags are among the most consistently PFAS-contaminated items in home kitchens. Make popcorn in a stainless steel pot with a lid using a tablespoon of oil and loose kernels. It takes 3 minutes and contains no PFAS.
Choose restaurants committed to PFAS-free packaging
Chains that have independently verified their packaging is PFAS-free include Whole Foods and some independent restaurants using certified compostable packaging. Look for packaging explicitly labelled PFAS-free.