Is it safe to microwave food in a polypropylene takeout container?

What's actually in it

Polypropylene ("PP," recycling code 5) is the plastic in most takeout containers, microwavable meal trays, and reusable food tubs. The "microwave safe" label only means the container won't deform or catch fire. It says nothing about what leaches into your food.

Heat softens plastic at the molecular level. Softer plastic sheds more particles and more additives. The microwave heats the food and the container together, which speeds everything up.

What the research says

A 2025 study in J Agric Food Chem filled polypropylene food containers with hot and cold water and counted the nanoplastic particles that leached out. Hot water released many times more particles than cold. Microwaving and repeated heat cycles pushed the numbers higher still.

The additives come along for the ride: phthalates, bisphenols, and antioxidants used to keep the plastic stable. Once in your food, the particles cross into your bloodstream and stay there.

Transfer takeout to a glass plate or bowl before microwaving. Ceramic works too, as long as it doesn't have metallic paint. Covering with a paper towel instead of a plastic lid cuts the load further.