Can styrene from plastic food containers migrate into your food?

What's actually in it

Polystyrene is the rigid or foamy plastic used for takeout containers, disposable cups, and some food packaging. It's made from a chemical called styrene, which is classified as "reasonably anticipated to be a human carcinogen" by the National Toxicology Program. Small amounts of unreacted styrene remain in the finished product and can leach into food.

Styrene is also found in the linings of some canned foods and in plastic cutlery. The warmer the food and the fattier it is, the more styrene migrates out.

What the research says

A 2025 review in Food Chem examined how styrene migrates from food contact materials into food. The researchers pulled together data on migration rates under different conditions: temperature, food type, contact time, and material type.

Hot, fatty foods pulled out the most styrene. Think hot soup in a styrofoam cup or leftover pizza reheated in its takeout container. Acidic foods like tomato sauce also accelerated migration. The longer food sat in the container, the higher the styrene levels climbed.

Some of the migration levels exceeded the limits set by the European Union for styrene in food contact materials. The review noted that daily exposure adds up quickly for people who regularly eat from polystyrene containers.

Glass, stainless steel, or ceramic containers are styrene-free alternatives. If you eat takeout, transfer the food to a plate before reheating. Never microwave food in polystyrene containers.