Do disposable paper cups leach microplastics and heavy metals into your coffee?

What's actually in it

Disposable paper cups aren't just paper. They're lined with a thin layer of polyethylene or PLA plastic to make them waterproof. Hot liquids soften this lining and pull particles into your drink. The inks and adhesives used on the cup can also contribute heavy metals.

Americans use an estimated 50 billion paper cups per year. Most people don't think twice about what migrates from the cup into their morning coffee.

What the research says

A 2026 study in Food Chem Toxicol tested disposable paper cups from multiple manufacturers for microplastic release, ion migration, and heavy metal contamination. They filled cups with hot water at typical coffee temperatures and measured what leached out.

Microplastic particles shed from the inner plastic lining into the liquid within minutes. Hotter liquids released more particles than warm ones.

The researchers also found heavy metals including lead and cadmium migrating from the cup material. Colored and printed cups released more metals than plain white ones.

Over a year of daily use, the cumulative exposure adds up. Switching to a reusable ceramic or stainless steel travel mug eliminates this source entirely.