E-Cigarettes: A Closer Look at Their Safety
E-cigarettes have gained immense popularity, particularly among younger individuals, over the past twenty years. Advertised as safer alternatives to traditional smoking, new research raises questions about this notion.
A study released on June 25 in the journal ACS Central Science examined three widely-used disposable vape brands for toxic metals and metalloids, including lead, chromium, antimony, and nickel. The inhalation of these harmful substances can elevate the risks of cancer, respiratory diseases, and nerve damage. The findings revealed that e-cigarettes emit significantly higher levels of these toxic metals compared to traditional cigarettes and other vape products. In fact, one brand released more lead in a day’s use than what could be found in nearly 20 packs of cigarettes. Given the alarming rates of underage vaping, the researchers emphasized the urgent need for regulatory measures.
“Our study emphasizes the hidden dangers of these trendy disposable e-cigarettes, which contain neurotoxic lead and carcinogenic nickel and antimony. This calls for immediate enforcement actions,” noted co-author Brett Poulin, an assistant professor of environmental toxicology at the University of California, Davis. “In some cases, the risks are not just worse than other e-cigarettes but even exceed those of traditional cigarettes.”
The FDA has been cracking down on brands selling flavored, disposable vapes in the U.S., spurred by concerns regarding youth access and health risks. Although the agency has issued warning letters, imposed civil penalties on retailers, and blocked imports from countries like China, it still struggles to keep these products out of the market.
Sales of disposable vapes have outpaced those of older refillable models in recent years. According to the FDA’s Annual National Youth Tobacco Survey for 2025, disposable e-cigarettes are now the top tobacco product used by young people. The survey revealed that 5.9% of middle and high school students, amounting to around 1.63 million, reported current e-cigarette use, with 55.6% of those favoring disposable options.
While previous studies focused on refillable e-cigarettes, few have examined these newer devices. To address this gap, Poulin and his team analyzed seven disposable vapes from three popular brands, looking at both flavored and unflavored liquids. They selected these brands based on their popularity and purchased the devices from U.S. online vendors. All except one of the vapes contained nicotine, allowing the researchers to explore how nicotine levels might affect the concentration of metals in the e-liquids.
The main components of any vape include a battery, e-liquid (often referred to as “vape juice”), and a heating coil. When a user activates the device, the battery heats the coil, converting the e-liquid into an aerosol. This process can lead to metals leaching from the components into the e-liquid, eventually being inhaled.
The researchers measured the metal concentrations in both unused e-liquids and aerosols, using specialized instruments to activate the e-cigarettes and generate between 500 and 1,500 puffs per device. They determined that “these disposable products have toxins that are either present in the e-liquid or leaching heavily from their parts into the liquid, and subsequently, into the smoke,” stated Mark Salazar, the lead author and a PhD candidate in Poulin’s lab.
Some of the unused e-liquids contained substantial amounts of antimony, a hazardous metalloid. Nickel leached into the e-liquid from the heating coils, while some components made from leaded bronze alloy also released nickel and lead. Notably, the vapors from certain devices exhibited unexpectedly high levels of metals, including antimony and lead. Interestingly, as the number of puffs increased, so did the metal concentrations in the aerosol, indicating that exposure may worsen as the device is used longer.
Overall, the researchers concluded that those using disposable e-cigarettes face significantly greater exposure to toxic metals compared to refillable vape users, potentially resulting in increased health concerns. Three of the tested devices emitted nickel levels that exceeded cancer risk limits, while two produced amounts of antimony that could be cancerous. Four devices surpassed risk thresholds for other health issues, such as neurological and respiratory damage.
This study examined only three out of nearly 100 disposable e-cigarette brands in the U.S. Despite regulatory measures, these devices continue to be exceedingly popular among young people. The researchers hope their findings will motivate further investigations into the health risks linked to disposable e-cigarettes, which seem unlikely to disappear anytime soon.
