The legal battle over lead in Stanley tumblers is heating up.

Consumers from four states – California, Nevada, New York and Washington – have filed a proposed class action lawsuit against Pacific Market International (PMI), alleging the parent company of the Stanley brand failed to disclose the presence of lead in the popular line of reusable drinkware, thereby putting the public at risk.

Plaintiffs had previously taken legal action separately, but a judge ruled that the lawsuits should be consolidated into a single case, a formal complaint for which attorneys filed on Tuesday, June 18. The court had denied PMI’s request to dismiss some of the cases in April.

The suit asks that PMI be made to pay punitive damages and to refund what consumers paid for the drinkware. The plaintiffs want that money to go to themselves and others who bought a Stanley tumbler with lead in it – a “class,” to use the legal term, that the consolidated complaint says “consists of hundreds of thousands, if not millions” of people.

The suit also asks the court to enjoin PMI from selling the Stanley drinkware until it stops using lead in the products. Furthermore, the suing consumers want PMI to be made to undertake an advertising campaign that alerts the public to the presence of lead and its alleged related dangers.

After videos started circulating on social media about Stanley lead concerns, PMI said in January that the material it uses to vacuum-insulate tumblers at their base contains some lead.

Prior to that, “PMI never disclosed that it made its cups with lead,” the lawsuit asserts. “Instead, PMI systematically deceived consumers by omitting that fact from its advertisements, displays and packaging.”

The suing consumers say they wouldn’t have bought the drinkware if they had known about the lead, accusing PMI of consumer protection law violations, deceptive trade practices, fraud by omission and more.

“Plaintiffs did not expect these cups to contain a toxic metal,” the lawsuit reads. “These cups are now worthless to them because they contain lead, and all Plaintiffs have stopped using them for fear of lead exposure.”

PMI has previously asserted that the lead in the drinkware’s base isn’t a health threat. Some health experts have said there is “practically zero risk” of lead exposure from Stanley tumblers, but the U.S. Centers for Disease Control and Prevention has noted that using lead in manufacturing creates “a risk of lead exposure for consumers of those products, especially for products intended for use in food consumption.”

Excessive lead exposure can cause adverse health effects ranging from cardiovascular problems and kidney damage to nervous system issues and slower growth/development in children.

Attorneys for PMI have yet to respond to the consolidated complaint with a formal legal filing.

Propelled to popularity in significant part by female social media influencers, Stanley tumblers have been popular sellers at retail and in the promotional products industry. ASI Media named the Stanley Quencher the 2023 Product of the Year in the branded-merch market.