Is it safe to drink coffee from ceramic mugs with painted exteriors?

What's actually in it

Ceramic mugs are usually lead-free and cadmium-free on the inside where the drink sits. The outside painted exteriors use different glazes that often contain heavy metals for color. When drinkers touch the painted exterior then bring the rim to their mouths, or when the painted area gets scratched and deposits chips into the drink, metal migration happens. Hand-painted and imported ceramics are the highest-risk category.

Novelty mugs with lots of decoration have the most metal-containing glaze.

What the research says

A 2025 study in J Hazard Mater measured migration kinetics of cadmium and lead from ceramic mugs. Commercial mugs with painted decorations had detectable metal migration into hot liquids. The effect was worse with acidic drinks (like lemon tea or hot cocoa) and with repeated use.

For coffee and tea, plain white ceramic mugs from established brands (Denby, Le Creuset, Williams Sonoma) are usually safest. Glass or stainless mugs skip the glaze question entirely. Avoid hand-painted imported ceramics without clear safety certification. Test suspect mugs with a lead swab test: positive results mean display-only use.