Do disposable paper cups release microplastics and metals into hot drinks?
Yes. A 2026 Food Chem Toxicol study found hot liquid changed the HDPE inner film of tested paper cups and released microplastics, ions, zinc, and aluminum.
Why paper cups are not just paper
Disposable paper cups usually need a thin plastic inner layer so hot drinks do not leak through the paper. In the tested cups, that inner film was HDPE, or high-density polyethylene.
Heat matters because hot liquid sits against that plastic layer while you drink.
What the research says
A 2026 study in Food Chem Toxicol tested 10 disposable paper cups from Turkiye marketplaces. The researchers found that the HDPE inner film changed structure when it touched a hot beverage.
After 15 minutes with hot liquid, the cups released microplastics, zinc, aluminum, ammonium, and chloride. The study reported 394.54 ppb zinc, 58.05 ppb aluminum, 1.07 ppm ammonium, and 17.49 ppm chloride in the tested conditions.
This does not mean one takeaway drink is a crisis. It does mean daily hot drinks in lined paper cups add avoidable contact with plastic and metals.
What you can do
Use glass, stoneware, or stainless steel cups for hot drinks when you can. If you buy a hot drink in a disposable cup, drink it sooner instead of letting it sit. For home coffee or tea, reusable cups are the simpler swap.
The research at a glance
| Study | Journal | Year |
|---|---|---|
| Monitoring of microplastics, ions and heavy metals in disposable paper cups from Turkiye marketplaces. | Food Chem Toxicol | 2026 |