When tested with an XRF instrument, this 2018 brown-glazed Starbucks-brand mug (purchased new at a Starbucks store in Washington State in 2019) had the following readings:
On a part with just the brown glaze:
- Lead (Pb): 513 +/- 29 ppm
- Barium (Ba): 2,820 +/- 101 ppm
On the unglazed ceramic bottom of the mug:
- Lead (Pb): 129 +/- 19 ppm
- Barium (Ba): 522 +/ 42 ppm
All tests were done for a minimum of 60 seconds each – using a freshly calibrated Niton XRF instrument (an XL3T XRF testing in “Consumer Goods” mode). Tests were repeated multiple times on each component to confirm the results. All test results reported on this blog are science-based, accurate, and replicable.
How much Lead is “too much” Lead?
For context, the amount of Lead that is considered unsafe (and illegal) in products “intended for use by children” is anything 90 ppm or higher in the paint, glaze or coating, and anything 100 ppm or higher in the substrate (in the case of a mug, this would be the base clay of the mug.) These standards are for XRF-detectable total Lead content (not Leach-test results – which is a different standard / different type of testing.) Dishes (including mugs) are not regulated in the same way as children’s items – as they are not considered to be “items intended for use by children.” In my opinion, this is a significant regulatory loophole — as, frankly, I don’t know any children who don’t use dishes.
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