Do Stanley cups contain lead? What you should know about claims, safety of the tumblers

Stanley cups, the trendy and coveted drinkware-turned-status-symbol, are still going viral. The latest question people are asking besides where to find the best deals? Whether they're safe to drink from.

A series of posts have appeared on TikTok and Facebook claiming that the insulated tumblers contain lead, thanks to clips and images of people seemingly performing at-home lead tests on their cups. Some of the tests turn up negative, while others are shown to the camera after changing color to indicate the apparent presence of lead.

Posted by average people as well as accounts like "Lead Safe Mama," a self-proclaimed advocate for lead poisoning awareness, some of the claims have taken off, leading people to share concerns that their hard-won cups could pose a risk to their health.

Do the cups really contain lead? Here's what we know.

Do Stanley cups contain lead?

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Why do netizens think Stanley cups are made with lead? Because they are - kind of.

A dot of material containing lead is used on the bottom cap to seal the insulated cups, a standard sealing practice used in insulated drinkware. However, the bit of lead is enclosed in stainless steel, meaning the lead does not sit on the surface of the tumbler, nor does it come in contact with your drink inside.

If you turn your insulated Stanley over, you will see a small circular cap on the bottom exterior of the cup. It is beneath this external seal that some lead can be found. Multiple videos testing the cups for lead do swab this bottom portion after removing the cap cover, as opposed to the inside of the cup.

"Please rest assured that no lead is present on the surface of any Stanley product that comes in contact with you or the contents of your container," Stanley International said in a statement to USA TODAY.

"Every Stanley product meets all U.S. regulatory requirements, including California Proposition 65, which requires businesses to provide warnings to Californians about heavy metal and chemical exposure."

In the statement, the company went on to explain, "We seal our vacuum insulated stainless steel products with an industry-standard pellet that includes some lead. The pellet is completely enclosed by a stainless-steel cover, making it inaccessible to users."

Are at-home lead test kits accurate?

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Social media users have posted their at-home lead tests using a variety of retail kits. While they have apparently received varying results, there has been no reputable indication that the cups contain or need to be tested for unsafe lead contamination, nor has there been any evidence of the cups causing any health issues for consumers.

One commonly used one, the 3M LeadCheck, is listed as being compliant with the Lead Renovation, Repair and Painting (RRP) Rule per the U.S. Environmental Protection Agency (EPA), and is considered reliable when determining "regulated lead-based paint is not present on wood, ferrous metal (alloys that contain iron), or drywall and plaster surfaces," but only when used by a Certified Renovator.

However, 3M announced plans to suspend the production and sale of 3M LeadCheck test kits in October 2023.

Only two other tests are recognized by the EPA to be compliant with RRP rules, which means they have achieved a 95% accuracy rate, including D-Lead and Commonwealth of Massachusetts lead test kits. The EPA only recognizes tests conducted by certified inspectors, risk assessors and RRP-certified renovators.  

So, how accurate are at-home lead tests as a rule? That's up for debate. If you want a result you can fully trust when testing anything for lead, the EPA suggests sending a sample to a National Lead Laboratory Accreditation Program certified lab.

How do you get lead poisoning?

Lead poisoning occurs over an extended period when lead builds up in the body. Children are more susceptible to lead poisoning and may become sick from it more quickly, especially those under the age of 6, as it can impact their development.

Lead exposure was once much more common, as lead-based paint was used in most homes and buildings. Regulations have since changed, but older buildings may still expel lead from old paint and dust. Contaminated air, water and soil or working in an industry with lead-based products also put people at increased risk of poisoning.

While no longer present in paint and gasoline state-side, lead is still used in batteries, solder, pipes, pottery, roofing materials and some cosmetics, according to the Mayo Clinic.

Keep in mind that extended exposure and high levels of buildup in the body are necessary for symptoms or poisoning to occur. According to Mayo Clinic, some symptoms of lead poisoning in children include:

• Developmental delay
• Learning difficulties
• Irritability
• Loss of appetite
• Weight loss
• Sluggishness and fatigue
• Abdominal pain
• Vomiting
• Constipation
• Hearing loss
• Seizures
• Eating things, such as paint chips, that aren't food (pica)
• Premature birth
• Lower birth weight
• Slowed growth

Symptoms of lead poisoning in adults can include:

• High blood pressure
• Joint and muscle pain
• Difficulties with memory or concentration
• Headache
• Abdominal pain
• Mood disorders
• Reduced sperm count and abnormal sperm
• Miscarriage, stillbirth or premature birth in pregnant women