Do plastic food containers release nanoplastics into hot water and drinks?

What's actually in it

Most reusable food containers and takeout containers are made from polypropylene (PP), the plastic marked with recycling symbol #5. It's considered one of the safer food-grade plastics, which is why it's everywhere in kitchens. But "safer" is relative. When polypropylene meets hot liquids, it sheds particles you can't see.

These particles are nanoplastics: fragments smaller than 1 micrometer, small enough to cross cell membranes and enter your bloodstream. They're too small to filter out and too small to taste or see.

What the research says

A 2025 study in J Agric Food Chem measured nanoplastic release from polypropylene food containers into both hot and cold water. The researchers used advanced detection methods to count and characterize the particles.

Hot water caused dramatically more nanoplastic release than cold water. Pouring boiling water into a PP container released billions of particles per liter. Even warm water, the kind you'd use for tea or instant soup, released far more particles than room-temperature water.

The particles were confirmed as polypropylene, matching the container material. Their tiny size means they can pass through the gut lining and circulate in the body. Once inside, they're difficult for the body to clear.

Never pour boiling water directly into plastic containers. Use glass or ceramic mugs for hot drinks. If you microwave food in plastic containers, transfer it to a glass dish first. For food storage, glass containers with silicone lids avoid nanoplastic contamination entirely.