Can polystyrene takeout containers leach styrene into hot food?

What's actually in it

Polystyrene is the white foam plastic used in takeout containers, coffee cups, meat trays, and egg cartons. It's cheap and lightweight, which is why restaurants and grocery stores love it. But polystyrene is made from styrene, a chemical classified as a possible human carcinogen by the International Agency for Research on Cancer (IARC).

Styrene doesn't stay locked in the plastic. It migrates into whatever food or drink is touching the container. Heat, fat, and acidity all speed up the process. So a hot bowl of soup in a foam container is the worst-case scenario.

What the research says

A 2026 review in Food Saf (Tokyo) compiled data on styrene migration from food contact materials. The findings confirmed that styrene transfers from polystyrene containers into food under normal use conditions.

Migration rates increased with higher temperatures and longer contact times. Hot, oily foods pulled out the most styrene. Even cold foods showed measurable levels after sitting in polystyrene packaging for several hours, like what happens on grocery store shelves.

Chronic low-level styrene exposure has been linked to nervous system effects, fatigue, and headaches. The review noted that daily exposure from food packaging adds up, especially for people who regularly eat takeout or drink hot beverages from foam cups. Switching to glass, paper, or plant-based containers eliminates this source entirely.