The Truth About Lead in Viral Stanley Tumblers

Stanley cups can’t seem to stay out of the spotlight. The popular 40-ounce drinking cups have captured the hearts (and wallets) of millennial and Generation Z shoppers, and are famous for selling out in minutes. But concerns over tumblers containing lead, a naturally occurring metal found in the Earth’s crust, have made headlines recently, leaving people distressed about their beloved cups.

On social media, people are putting their travel tumblers to the test with at-home lead testing kits, and the results are mixed. While some people’s cups have come up clean, others have discovered that their tumblers — including those made by Stanley and other brands — contain lead.

Lead is toxic when ingested and can contribute to numerous health conditions, such as anemia, high blood pressure and cognitive deficits. But public health experts say that it’s unlikely you’re going to get sick from drinking out of your average tumbler.

“The risk of these cups is infinitesimally small,” said Dr. Andrew Monte, a professor of emergency medicine and medical toxicology with the University of Colorado Anschutz Medical Center.

“People do not have to be concerned about using these products, though if the cup is severely damaged, and the lead is accessible, throw it out,” Monte told HuffPost.

According to Stanley’s website, its popular drinkware is made with lead, but that part of the cup is tightly sealed off with a durable stainless steel layer.

“Rest assured that no lead is present on the surface of any Stanley product that comes into contact with the consumer nor the contents of the product,” the website states. “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.”

Jack Caravanos, a clinical professor of environmental public health sciences at the NYU School of Global Public Health, personally tested a few Stanley tumblers with an X-ray fluorescence instrument that can detect various metals, and didn’t find any lead. This suggests that the metal is buried deep within the cup, he said.

According to Monte, the cup would have to be incredibly damaged for its lead plug to pop out of the drinking canister.

“This type of damage would have to be so severe that the canister wouldn’t hold liquid anymore, so this doesn’t represent a realistic possibility,” Monte said. 

Still, public health experts argue that products people use for eating or drinking shouldn’t contain any lead. While the risk of being exposed to lead is low, there’s still a chance that you could ingest lead if a product cracks or breaks, according to Dr. Maryann Amirshahi, a co-medical director of the National Capital Poison Center.

“If the product is defective or damaged, or if the seal breaks down over time, then that is a cause for concern,” Amirshahi said. “It is important to remember that a broken seal may not always be obvious.”

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