Social media fueled the Stanley Quencher’s rise in popularity, and now it’s questioning the ubiquitous tumbler’s safety.

Over the past week or so, many customers have taken to TikTok and X (formerly Twitter) to share stories about using at-home tests to determine whether there’s lead in any of their Stanley products.

Although they’re receiving mixed results, the drinkware company has responded to viral concerns.

Stanley’s Response

Although lead is used as part of the tumbler’s vacuum insulation, it’s covered by a stainless steel layer that protects consumers from lead exposure, according to Pacific Market International, which manufactures Stanley drinkware.

“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,” a Stanley spokesperson told CNN. “Once sealed, this area is covered with a durable stainless steel layer, making it inaccessible to consumers.”

If the stainless steel barrier comes off – which a Stanley spokesperson told TODAY.com is “rare” – then consumers would come into contact with the lead. Meanwhile, the spokesperson added that Stanley’s engineering and supply chain teams are making progress on innovative, alternative materials for use in the sealing process.

“Rest assured that 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 Stanley spokesperson said.

Promo Suppliers Weigh In

Multiple suppliers in the promotional products industry who carry Stanley drinkware are well aware of the recent controversy.

“Stanley has passed safety and compliance tests – all compliance documents are accessible on PCNA’s asset portal and our product pages,” says Liz Haesler, global chief merchandising officer at PCNA – ranked the No. 7 supplier in the inaugural PPAI 100.

“Transparency is key to trust, and we ensure that our customers have unimpeded access to all relevant product safety information. We’ll continue to listen to feedback from the industry and investigate all safety concerns across our assortment of products.”

“This was a case of social media gone a little wild, as it can do from time to time,” says Brian Porter, chief revenue officer at Starline – ranked the No. 13 supplier in the PPAI 100. “At the end of the day, the safety risk is between non-existent and extremely low.”

Starline says it began manufacturing with a lead-free sealing process for vacuum drinkware in 2017, becoming the first promo supplier to implement the technology.

“When you start talking about lead in anything, it resonates a certain way, as it should,” Porter says. “So, you have to go to the next level and understand where the lead is and why it’s used. This manufacturing process has never been a concern as far as the safety of the consumer.”

How Did The Stanley Quencher Become So Popular?

The Stanley Quencher was arguably the hottest promotional product of 2023.

After all, drinkware (mugs, tumblers and bottles) is always in SAGE’s monthly list of top 10 product categories, and this past December, the 30-oz. and 40-oz. Stanley Quenchers took the No. 1 and No. 4 spots, respectively. Several suppliers offer a variety of brandable Stanley drinkware.

NBC’s Today show reported that a 2017 post by “a popular mommy blogger” – followed by a swift and savvy response by Stanley to release the product in new colors and appeal to new markets – sparked the current craze.

Word spread like wildfire online, spawning countless TikTok videos and billions of views. Forbes reports that #stanleycup has more than 6.7 billion views on TikTok alone. And the company’s revenue has increased tenfold in the past four years.