Young adults do not know what is in the products they vape, and what brand of products they use, according to a study published on Monday.
Researchers from the Stanford University in the US carried out the study on 445 California residents aged between 17 and 24.
The study, published in the Journal of Adolescent Health, asked the participants about their use of pod-based e-cigarettes, including specific questions about products made by Juul, Suorin Drop, Phix and Myblu.
Pod-based e-cigarettes are vaping devices that consist of a small plastic pod of nicotine-infused fluid that snaps into a vaporiser powered by a rechargeable battery.
"These young people had no idea how much nicotine they were consuming," said the study's senior author Bonnie Halpern-Felsher, a professor at Stanford University.
The findings raise concerns about how Juul and similar vaping products are labelled and regulated, Halpern-Felsher said.
The data were collected in early 2019 as part of the Tobacco Perceptions Study, a longitudinal study of tobacco and nicotine use, perceptions, and susceptibility to marketing among California youth.
Participants completed a questionnaire with detailed questions about their history of nicotine consumption, including use of cigarettes; pod-based e-cigarettes, such as Juul, and other types of e-cigarettes.
In addition to patterns of use, the participants were asked about their reasons for using pod-based e-cigarettes.
They were also asked about their perceptions of the nicotine content of these products.
The study found that 26.3 per cent of participants had used Juul, while 24 per cent had smoked traditional cigarettes.
As many as 23 per cent had used nonpod-based e-cigarettes and smaller proportions had used other pod-based e-cigarettes.
Among the participants who had tried a nicotine product, 51.3 per cent of those who reported trying Juul had vaped with the device over the last 30 days.
28.6 per cent of those who reported trying a cigarette had smoked one within the last 30 days, and 28.7 per cent of those who reported trying a nonpod-based e-cigarette had used such a device over the last 30 days.
About half of users of pod-based e-cigarettes said they shared pods with friends, and nearly half did not know if they always used cartridges sold under the same brand name as their devices.
The most concerning finding, Halpern-Felsher said, was that young people did not know how much nicotine was in the products they were using.
At the time the surveys were completed, Juul packaging just said "5 per cent", and the label has since been changed to say "5 per cent nicotine."
However, young adults were unable to calculate what this meant in terms of the actual quantity of nicotine, or to compare it accurately with the amount in combustible cigarettes, the survey found.
"If we asked how many milligrammes of nicotine are in a Juul pod, for example, we found the answers were all over the place," Halpern-Felsher said.
"The Juul and other pod-based e-cigarette packaging is so confusing and misleading. The packaging should be regulated," he said.
