As an owner of these and other double wall stainless cups made in China, I wanted more information than this paywalled article. Somebody should start a lemmy instance that bans all paywall links.
Anyway the company was very diligent at preventing this but it still happened. See here:
For anyone interested in facts and not headlines, the lead is on the exterior of the cup, in the bottom under the powder coated paint. It’s a seal disc in the bottom. Lead poses a threat to health only if ingested. For this lead to be ingested you’d basically have to destroy the cup.
This part was interesting:
tested the top selling household kids cup brands and found lead under the stainless steel discs for every single kids cup brand.
I think it would be safe to assume you’ll find lead in the seal disc on the bottom of any double wall stainless made in China.