(KTXL) — As the frenzy over Stanley cups continues across social media and in U.S. retailers, the Stanley company is responding to concerns over the presence of lead in its popular insulated cups.

Claims about the drinkware’s lead content bubbled up over the past few weeks, with some TikTok videos showing users testing Stanley cups for lead with at-home swab tests. Questions about the presence of lead, which is a natural metal that’s toxic to the human body, have caused Stanley to address the topic this week.

“Yes, Stanley uses lead in its manufacturing process for its cups, but they only pose a risk of lead exposure if the cover on the bottom of the tumbler comes off and exposes the pellet used to seal the cup’s vacuum insulation,” a Stanley spokesperson told TODAY.

The cover on the bottom that the representative is referring to is a round part on the bottom of the cups. That part can come off, if damaged, causing the lead pellet hidden inside to become exposed.

Stanley said no lead is present on the surface of any Stanley product that would come into contact with beverages.

In a separate statement to FOX Business, Stanley PMI, the manufacturing company, explained how the lead is used.

“At Stanley, one of the key features of our products is our vacuum insulation technology, which provides consumers with drinkware that keeps beverages at the ideal temperature,” Stanley PMI said. “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.”

So now you may still be worried: are Stanley cups safe to drink out of?

Stanley representatives are confident that their cups don’t pose any risk as long as the lead barriers on the cups aren’t compromised.

“All Stanley items comply with Prop 65 and FDA requirements,” Stanley said on its website. “Also, all contact surfaces are guaranteed to be safe and BPA-Free. The steel we use is 18/8, or grade 304, otherwise known as food-grade stainless steel. Like all of our products, our stainless-steel items must pass rigorous health and safety tests before making them available to the public.”

Consumers with questions or concerns about a potentially damaged or defective Stanley cup can contact Stanley directly.