How quickly do heavy metals leach from ceramic mugs into hot drinks?
A 2025 study found lead and cadmium migrated from ceramic mug surfaces, with higher migration from decorative exterior lip areas than interiors.
What's actually in it
Some ceramic mugs use glazes or decorative pigments that contain lead or cadmium. The biggest concern is paint or glaze on the rim, where your mouth touches the mug.
Acidic liquids can pull metals from ceramic surfaces. The study used 4% acetic acid, a standard test liquid for food-contact migration.
What the research says
A 2025 Journal of Hazardous Materials study measured cadmium and lead migration from new and second-hand ceramic mugs over 24 hours.
Migration was higher from exterior lip-area surfaces than from interiors. Exterior 24-hour concentrations reached about 115 micrograms per liter for cadmium and 934 micrograms per liter for lead in the highest cases. Interior levels were much lower.
The study does not prove that every ceramic mug contaminates coffee in 10 minutes. The practical step is to avoid mugs with paint or glaze on the rim. Use plain certified mugs, or choose glass cups for hot drinks.
The research at a glance
| Study | Journal | Year |
|---|---|---|
| Migration kinetics of cadmium and lead from ceramic mugs. | J Hazard Mater | 2025 |