A CT Scan Shows Where the Lead Is Located in Stanley Cups

A CT scan of Stanley’s viral Quencher cup has confirmed what the company has been saying all along: There’s only lead at the bottom of the cup. The lead is covered by a stainless steel cover, which Stanley says makes it “inaccessible to customers.” In the end, though, lead exposure might come down to a matter of luck.

The team at Lumafield, a hardware manufacturing company that makes CT scanners, ran Stanley’s Quencher tumbler through one of their machines last week. While videos of positive results from at-home lead tests (which expert warn can be unreliable) have led to endless speculation over what parts of the cups have lead, Lumafield’s CT scan showed that there was only lead at the bottom of the Stanley Quencher.

The lead identified by Lumafield, which is distinguished by the dark red circle on the CT scan, is the lead pellet used by Stanley to solder its cups. Stanley’s tumbler cups feature an inner and outer wall made of stainless steel that is welded together at the rim. Between those walls is a vacuum of insulation, which is what minimizes heat transfer and helps keep your beverage warm or cold.

Stanley says it uses a lead pellet to seal the vacuum insulation at the bottom of the cup. The company then covers the lead pellet with a stainless steel disk, the same material used for the rest of the tumbler.

So, what does this CT scan tell us? First, it means that Stanley wasn’t lying: There was only lead at the bottom of the tested cup. But that doesn’t mean that people with Stanley cups are completely safe from lead exposure, which can cause serious health problems for children and adults.

“[O]ur CT cross-section shows that the lead is entirely shielded, and its user won’t be exposed to lead at all. If the medallion covering the lead solder is pried off, it might become accessible—but in that case, a replacement cup is covered by Stanley’s warranty.” Bruner said.

The keyword here is the medallion, or the stainless steel disc covering the lead. In other words, while the CT scan clearly showed us where the lead in Stanley’s cups is, it also showed us that the only thing protecting people from exposure is a small metal disc that can theoretically fall off or become unsealed.

Lead safety activist Tamara Rubin told Gizmodo in February that she’s received hundreds of reports of people stating that their base cap has fallen off after normal use.

“In the last couple of days alone, I’ve had something like 300 people contact me and tell me that that disc on the bottom of their Stanley’s fell off within a week or a month of normal use,” Rubin said, adding that if people touch the lead pellet inside their cups and then touch food, they could expose themselves to lead.

Stanley, for its part, states that the stainless steel cover coming off is “a rare occurrence.”

While experts say there is no risk to using Stanley cups that are in perfect condition, do you really want to take the risk? There are plenty of alternative cups, such as Stanley’s lead competitor Hydro Flask, out there that don’t contain lead. (To be fair, Hydro Flask used lead in its cups until it invested in going lead-free.)

“As consumers become more discerning about the products they buy, the pressure on companies to not compromise on safety or sustainability will only increase,” Lumafield wrote in a post about its experiment.

We’re looking at you, Stanley.