Do disposable paper cups contain microplastics and heavy metals?

What's actually in it

Disposable paper cups aren't just paper. They have a thin plastic lining (usually polyethylene) inside to make them waterproof. Some cups also contain printing inks, adhesives, and bleaching chemicals in the paper itself. When hot coffee or tea sits in the cup, that plastic lining softens and sheds particles into your drink.

The paper component can also leach metal ions from the inks and coatings used to decorate the outside of the cup. What looks like a simple paper cup is actually a layered chemical delivery system when filled with hot liquid.

What the research says

A 2025 study in Food Chem Toxicol tested disposable paper cups from marketplaces in Turkey for microplastics, metal ions, and heavy metals. The researchers filled cups with hot water at various temperatures and measured what leached out over time.

They found microplastic particles in the water from every cup tested. The plastic lining was the clear source. Hot water released highly more particles than cold water, and longer contact times made it worse.

The cups also released metal ions including aluminum, zinc, and traces of lead. These came from the paper component, likely from recycled fibers and printing inks. The levels varied between brands, but all cups released some combination of plastics and metals.

Bring a reusable ceramic or stainless steel travel mug for your daily coffee. If you must use a paper cup, let the drink cool slightly before sipping. Avoid leaving hot drinks sitting in paper cups for extended periods.