Do hot drinks in plastic cups release chemicals?

What's in the cup

Disposable plastic cups are made from polystyrene, polypropylene, or PET. They contain plasticizers, stabilizers, and colorants that aren't permanently locked into the plastic. Heat loosens these additives and pushes them into whatever liquid is inside.

When you pour hot coffee, tea, or soup into a plastic cup, the temperature accelerates chemical migration. The hotter the drink, the more the plastic releases.

What the research says

A 2026 study in J Hazard Mater tested what chemicals leach from disposable plastic cups into liquids and found they are neurotoxicants. The leachates contained a mix of plasticizers and stabilizers that damaged neural cells in lab tests.

The chemicals disrupted specific gene regulation pathways (including miR-330-3p and histone modification), which are involved in how brain cells grow and communicate. While this study focused on alcohol as a solvent, heat acts similarly by breaking down the chemical bonds between additives and the plastic matrix.

Other research on hot liquids in plastic and paper cups has confirmed that temperatures above 70°C dramatically increase particle and chemical release from cup walls.

How to reduce your exposure

Bring a reusable ceramic or stainless steel mug for hot drinks. If you have to use a disposable cup, let the drink cool before pouring, or choose a paper cup with no plastic lining. Avoid microwaving drinks in plastic cups.