We Tested Bubble Tea for Lead. Here's What We Found.
The boba pearls in the drink are made from cassava, a known source of the heavy metal
Bubble tea is everywhere. In plenty of downtown areas, it’s hard to miss people walking about carrying cups of the beverage, sipping through extra-wide straws designed to suck up the boba—the chewy little gelatinous tapioca pearls that give bubble tea its distinctive appearance.
The delicious and refreshing treat originated in Taiwan in the 1980s, and it has spread rapidly around the globe in the decades since. Bubble tea cafés have flourished in the U.S. in recent years, becoming popular gathering places in many communities, especially among Asian Americans. In 2024, there were 6,635 bubble tea shops across the country, according to market research group IbisWorld—and that number is expected to double by 2028. But you don’t need to leave home to indulge—you can buy boba pearls and kits to help you make your own. There are many variations on the drink, but the traditional preparation is straightforward, containing brewed tea, milk or creamer, some sort of sweetener or flavor, and boba.
Tapioca is made from cassava, a root vegetable. Recent tests by Consumer Reports found that cassava-containing products sometimes had very high lead levels, so our experts recently ran a small test on boba pearls to see how much lead and other heavy metals they might contain.
The good news: None of the boba tested above CR’s level of concern for lead. “These levels weren’t so high that we’d tell people to completely avoid bubble tea,” says James E. Rogers, PhD, director of food safety research and testing at CR. “However, while this wasn’t a comprehensive look at the boba and bubble tea market, the fact that three out of the four boba samples contained more than 50 percent of our level of concern for lead in one serving is a good reason to treat it as an occasional treat, not an everyday staple.”
What CR’s Testing Found
To determine the heavy metal levels—arsenic, cadmium, lead, and mercury—in boba, CR researchers tested the pearls from bubble teas from two popular chains (Gong Cha and Kung Fu Tea) and two packaged boba products (from Trader Joe’s and WuFuYuan). We tested three samples of each product. For the tea shop drinks, the liquid and the boba were tested separately (more on that below). For more information on our tests, see our methodology sheet (PDF).
Lead Levels in Boba
| Product | Serving Size | Percentage of CR's Level of Concern for Lead |
| Trader Joe’s Instant Boba Kit1 | 1 pouch (65 grams) | 83% |
| Gong Cha Pearl Milk Tea (tapioca pearls only) | 87 grams2 | 70% |
| Kung Fu Tea Milk Tea with Boba (tapioca pearls only) | 87 grams2 | 63% |
| WuFuYuan Tapioca Pearl, Black Sugar Flavor | 1/3 cup (50 grams)3 | 29% |
Lead is particularly pernicious during pregnancy and for young children because it can have serious adverse effects on the developing brain and nervous system. But too much lead is harmful to anyone—for example, adult lead exposure is responsible for approximately 256,000 cardiovascular disease deaths each year, says Tom Neltner, national director of Unleaded Kids, a group working to protect kids from lead exposure.
In a multi-ingredient product like bubble tea, lead could come from multiple sources: the boba pearls, the sweetener, the tea itself, or the water used to make it, or the milk, juice, or other liquids that might be added. So while the purpose of our tests was to see whether boba could be a significant source of lead, we also measured lead in the liquid portion of the two bubble teas from the tea shops in our tests to see what the added lead exposure might be. In those cases, we found even more lead per serving in the liquid than in the boba pearls.
It’s difficult to tell where the lead in the liquid portion of the bubble teas came from, says Sana Mujahid, PhD, manager of food safety research and testing at Consumer Reports, who oversaw the testing. It could be from the water or the equipment used at a particular shop. The three samples of each tea were all purchased from shops in the same area. It’s possible that lead levels in bubble teas from these chains would vary depending on the location of the shop.
We contacted the four companies whose products we tested, sending them our test results and asking for comment.
Trader Joe’s informed us that it has discontinued its Instant Boba Kit, but did not provide any further comment.
Jason Tsou, General Manager at WuFuYuan’s parent company, Shanghai ZhouShi Foodstuffs, said: “We take the safety of our products very seriously, and your outreach has prompted us to further improve our existing quality control measures.” He said the company already works with an accredited lab to test its ingredients and finished products for lead, and has now implemented a more stringent standard.
Gong Cha and Kung Fu Tea did not reply to our request for comment.
Why Is Lead in Tapioca?
Lead is naturally found in the Earth’s crust. There’s also significant lead contamination in much of the world’s soil due to industrial pollution and the past use of leaded gasoline and lead-based pesticides.
Because they are grown in soil, many fruits and vegetables absorb heavy metals. Root vegetables such as carrots, cassava, and sweet potatoes are all known to pick up lead. Tapioca appears to have less lead than raw or less processed cassava (such as cassava flour), likely because some is removed during the washing and pulping process of extracting tapioca from the root. However, a significant amount remains.
Advice for Consumers
Having one serving of boba from these sources a day would not put you over CR’s level of concern for lead. However, lead can be in a variety of foods, and your daily exposure can add up. While you can’t completely avoid lead, you can consume products known to contain it in moderation. That’s especially the case for foods that are optional treats, not key parts of your diet, like bubble tea and dark chocolate.
In addition, eating a variety of healthy foods in general can help you avoid overconsumption of heavy metals. And getting enough of certain nutrients, such as calcium, iron, selenium, vitamin C, and zinc, may help offset some of the harm heavy metals do in the body.
