New lawsuit claims Stanley tumblers 'failed to disclose presence of lead'
The trendy oversized Stanley thermos that reached viral fame on social media and became a must-have item is facing new criticism from customers.
The parent company of the viral tumblers is facing two lawsuits after Stanley acknowledged that part of the insulation at the bottom of the bottle -- which people do not come into contact with -- contains some lead.
In one of the lawsuits filed last week, Mariana Franzetti alleges the company, Pacific Market International, "engaged in a campaign of deceiving customers by failing to disclose the presence of lead in its tumbler products."
The lawsuit also claims the company "knew or reasonably should have known about this lead issue for years but chose to conceal it from the public presumably to avoid losing sales."
The cups are still available for sale online.
Pacific Market International did not immediately respond to ABC News' request for comment.
"When I discovered that lead was possibly in the Stanley cup, I was really upset," Franzetti told ABC News. "I tried to treat my body as well as possible. I wouldn't have bought any sort of product that had lead in it, to my knowledge. And I just thought, why is a company like this being so deceptive?"
Last month, several customers said they performed at-home tests on the cups -- with some allegedly testing positive for lead.
Stanley released a statement in response saying the material used for the insulation seal at the bottom of the products does contain "some lead," but that it is covered with stainless steel and "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 company told USA Today in response to the lawsuits that it will "vigorously defend itself against meritless claims."
"My trust has been shaken in the company, but I would like to see them not just with the Stanley cups currently, but with all their products, make a commitment to being lead-free," Franzetti said.
Stanley cups have gained massive popularity in recent months. In January, videos across social media showed shoppers at Target clamoring for the brand's limited edition "Galentine's Day" red and pink tumblers.