Concern over lead exposure in Stanley cups rise as lead poisoning activist, Tamara Rubin (Lead Safe Mama), brings attention to the presence of lead in their tumblers on TikTok in March 2023 with her at-home lead testing kits. Stanley assures that the risk is low, but the existing risk still garners attention. 

Following the attention to the lead found in the base of their tumblers, Stanley released an official statement regarding their manufacturing process:

“Our manufacturing process currently employs the use of an industry-standard pellet to seal the vacuum insulation at the base of our products; the sealing material includes some lead. Once sealed, this area is covered with a durable stainless steel layer, making it inaccessible to consumers…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” (Stanley). 

The lead is melted at the base of the cups to create the vacuum insulation, hidden by a small button. The button is made of stainless steel, effectively creating a barrier between the dangerous metal and the consumer. 

Science teacher Charles Yu explains the role of the stainless steel base in the tumblers that is effective in keeping out the lead. 

“Lead molecules are large and stainless steel is not very porous, so the molecules cannot penetrate through the base,” said Yu. 

Rubin’s activism began when her son was exposed to lead paint dust and suffered severe brain damage as a seven month old. She has been bringing awareness to the dangers of lead to other parents online through her content, including the use of at-home lead testing kits. Parents and others who have found her content have tested their own Stanleys at home as well, especially if the protective base has come off. 

“Though some people say [the] protective disc doesn’t come off easily, I’ve heard from many people who say that for them it has,” said Rubin. 

Other water bottle manufacturers have been able to use alternate ways to insulate their reusable water bottles, such as Hydroflask, who changed their lead sealant in mid-2013. Other heavy metals that don’t accumulate in the nervous system and with similar chemical and physical properties could be used as alternative insulating materials according to Yu. The health risks that come with the heavy metal toxin include nervous system problems for all ages and development issues for children especially. 

However, with the protection of the stainless steel base, it seems that sophomore Armaan Jain isn’t worried about his tumbler. He quickly became a fan of Stanley cups as they became more popular, even convincing some of his friends to get their own Stanleys. 

“They store a lot of water, are durable and are easy to use,” said Jain.

The craze for Stanley tumblers blew up all over social media. With the simple design and many colors of the cups, getting used to the cups became habitual and because of its eco-friendly reusable function, social media has marketed them to be a lifestyle marked by clean, responsible, well-hydrated order. Even with the scare, it seems that Stanley fans, such as Jain, are sticking with their high quality tumblers.