Should I Be Worried About Lead in My Stanley Cup?

It’s the classic life cycle of a wellness trend: “Have you heard about this thing?” segues into “You’ve got to try this thing!” segues into “Wait — this thing might be harming you.” The latest trend to hit stage 3 is the endlessly viral Stanley tumblers — but the reports of the dangers of TikTok’s most famous water bottles may be greatly exaggerated.

Videos of tweens weeping with joy while unwrapping Stanley tumblers on Christmas morning have led to yet another spike in the water bottles’ popularity. But with that new attention came claims that Stanley cups contain lead.

This isn’t an entirely new rumor. Questions about Stanley tumblers containing lead first began circulating last year; one mom’s post on TikTok alleging that her toddlers’ water bottle tested positive for lead went especially viral.

But with videos of TikTokers lead-testing their Stanleys bubbling up again recently, we decided to ask an expert to break down exactly what you need to know about these heavy metal claims. Spoiler alert: there’s likely no need to throw out your beloved tumbler just yet.

Why Do People Think Stanley Tumblers Contain Lead?

In a since-deleted video that was posted to TikTok in summer 2023, a parent showed herself using an at-home lead test on the bottom center of her toddlers’ Stanley tumbler — and the test came up positive for lead. (You can see screenshots on the Daily Dot.)

That video became very popular and led to other people filming themselves testing their water bottles for lead, but it wasn’t the first time someone had raised the question of lead in vacuum-insulated water bottles. A few months prior, Tamara Rubin posted about Stanley tumblers and the lead used in their manufacturing to her blog, Lead Safe Mama.

Is There Lead In Stanley Cups?

Technically, there is lead in Stanley tumblers, and most vacuum-insulated water bottles — but it’s very rarely a risk to consumers.

Stanley itself acknowledges that the company uses “an industry standard pellet to seal the vacuum insulation at the base of our products; the sealing material includes some lead,” per the Stanley website’s FAQs. (When POPSUGAR reached out to a representative for Stanley for comment, they directed us to their FAQs.)

Most vacuum-insulated reusable water bottles use lead soldering because it’s the easiest and cheapest method, says Jun Wu, PhD, a professor of environmental and occupational health at UC Irvine Public Health. “It’s not just Stanley.”

That said, the lead solder is completely enclosed by stainless steel and should not come in contact with your drink, says Dr. Wu. “The risk of lead exposure is really low unless the protective cover is missing or impaired,” she explains.

According to screenshots seen in the Daily Dot, in the original video posted to TikTok, the protective cover did appear to be missing, which could explain why the mom’s lead test came up positive. The Stanley FAQs note, “In the rare occurrence the base cap of a product comes off due to ordinary use and exposes this seal, it is eligible for our Lifetime Warranty.”

Also worth remembering: every trace of lead doesn’t actually get into your bloodstream, Dr. Wu says. “It’s one thing for lead to be in the environment and in consumer products, but it’s another thing on how much lead actually gets in your body,” she explains. “Lead is definitely bad, and we want to minimize its use in the environment, but we don’t know how much lead in the solder is bioavailable and can actually be absorbed into the body.”

Aside from the small solder, the main body of the tumbler is made with recycled stainless steel and a powder coat finish, which Stanley guarantees to be safe and BPA-free. Even better, all Stanley products are FDA tested and approved and safe to use with food and beverages.

Did Stanley Recall Tumblers For Lead Poisoning?

No. Stanley has not recalled tumblers for lead poisoning and there is no lead present on the surface or inside of the cup. Any small traces of lead would not taint your water and there is no real risk of lead exposure, says Dr. Wu.

“People have a right to be concerned, but I don’t think they need to be super concerned,” she explains. “There is a risk if the protective layer is missing, however the risk would be relatively low in my opinion.”

While the chance of lead poisoning is extremely minimal, if you’re concerned, the best way to test whether you’ve been exposed is through a blood test, says Dr. Wu. Relatively low lead exposure doesn’t present with clear signs or symptoms, and a blood sample is the only real way to determine lead levels in the body, she explains.

If the cover comes off the bottom of your bottle, play it safe and contact Stanley about their lifetime warranty. Another option: finding a reusable water bottle brand that clearly states they use lead-free solder, Dr. Wu says. Or consider an all-glass bottle, like the Lifefactory Flip Cap Glass Water Bottle ($23).