Stanley tumblers, which sparked a massive craze and even sold-out shortages among America's millennial and Gen Z consumers, have been cleared of lead-related concerns.
A federal district court in Seattle dismissed a class action lawsuit filed by consumers alleging that Pacific Market International, the maker of Stanley tumblers, concealed the presence of lead in its products, Reuters reported Monday (local time).
In a 41-page ruling, Judge Tana Lin said the consumers "failed to demonstrate a concrete and plausible risk of harm from lead due to the use of tumblers manufactured by Pacific Market International." She added that "there is no basis to conclude that the mere presence of lead is dangerous, or that lead pellets used in manufacturing the tumblers could contaminate the contents, or be ingested or inhaled." Judge Lin gave the plaintiffs an opportunity to amend their complaint but stated the case would be dismissed with prejudice if they failed to address the deficiencies.
The controversy began in 2024, when Stanley tumblers were at the peak of their popularity, after videos went viral on social media. According to CNN and other outlets, some users posted videos on TikTok and other platforms showing lead testing kits producing a reaction when applied to Stanley tumblers, sparking public concern.
As consumer worries grew, Stanley responded that "industry-standard pellets are used to seal the vacuum insulation at the bottom of the product during manufacturing, and these pellets contain lead." The company explained that "while materials containing lead are used in the manufacturing process, they do not come into direct contact with consumers, so there is no cause for concern." Stanley said the lead used as a sealant would not become exposed unless the tumbler is damaged, subjected to extreme heat, or used in ways inconsistent with its intended purpose.
Jena Forsyth, a research scientist studying lead exposure at Stanford University School of Medicine, said the likelihood of lead exposure from Stanley tumblers is very low, and even lower when compared to other environments where consumers may encounter lead, such as batteries or paint.
However, consumers argued that "had they known about the risk of lead, they would not have purchased Stanley cups or would have paid a lower price," and proceeded with the class action lawsuit. Forsyth also argued that companies should use alternative materials to replace lead. "Companies should not use lead in their products unless it is absolutely necessary," she said.
In fact, competitor Hydro Flask said it "has not used lead in the process of sealing vacuum insulation for more than 10 years." Another manufacturer, Owala, also stated on its website that "our beverage containers do not contain lead."
Lead is a toxic heavy metal that, once absorbed into the body, takes longer to be expelled than other heavy metals. According to the U.S. Centers for Disease Control and Prevention (CDC), lead absorption can cause kidney problems, anemia, and reproductive and developmental issues.