NEW YORK – Ms Alexa Addison remembers what vapes looked like when she was in high school. The dominant e-cigarette was Juul, a slim, black rectangle with sharp corners that resembled a flash drive.

By the time Ms Addison, 19, started college at the University of North Carolina Wilmington in 2022, the vape du jour had shifted. She saw many of her classmates brandishing Elf Bars, brightly coloured e-cigarettes that looked like ombré AirPods cases, with gently sloped chimneys for inhalation.

She bought flavours like piña colada and strawberry-kiwi, and took pictures when the candy-coloured gradients of the devices coordinated with her outfits.

Soon, she found herself going through an Elf Bar a week. (Each one contains as much nicotine as 590 cigarettes, according to one estimate.) Ms Addison said during her period of most intense use, her gums turned grey.

“They looked really pretty, honestly,” she said of the devices. “I just never had an interest in vaping until the pretty ones started being sold.”

About five years after Juul became many people’s mental image for the word “vape”, e-cigarettes are in the midst of another face-lift. The understated look associated with Juul has been edged out by the rounded, vivid designs of Elf Bars and other brands, whose colour schemes often correspond with their flavours.

In interviews, young people compared the appearance of these disposable e-cigarettes to candy, pacifiers, lip gloss and soap.

“They almost look like toys,” said Mr Carter James, 23, a music producer who lives in the Brooklyn borough of New York, and said he stopped using e-cigarettes over the summer.

Some public health experts are concerned that the playful appearance of these devices – which is neatly in line with the maximalist aesthetic preferences of Generation Z – may offer appealing new cover for nicotine products.

Doctors say nicotine is especially addictive for young people, and research suggests that teenage vapers risk both immediate and long-term lung damage.

In combination with candy- and fruit-inspired flavours – a major focus of anti-tobacco groups – alluring vape packaging could steer young people toward e-cigarettes, several experts said.

“If it looks glamorous and it looks appealing, that’s going to be the first driver that will bring a horse to water,” said Mr Brian King, chief of the Food and Drug Administration’s (FDA) tobacco centre. “The flavours then get them to drink. And the nicotine keeps them coming back for more.”

Joe Camel for Gen Z?

Dr Susan Linn, a psychologist and lecturer in psychiatry at Harvard Medical School, said there was “no question” that the appearance of Elf Bars was geared to catch the eyes of adolescents or even children, who gravitate toward bright colours and rounded shapes.

She compared the juvenile look of Elf Bars to Joe Camel, the cartoon character retired by R.J. Reynolds Tobacco after years of criticism that it was targeted at children.

Decades later, e-cigarette companies also made visual appeals to young people: In 2018, the FDA issued warnings to companies that sold nicotine products that looked like juice boxes.

“Tobacco companies use cartoons or brightly coloured packaging in order to hook kids, to make kids think that this is benign, fun and harmless to them,” said Dr Linn, who is also the author of Consuming Kids, a book about marketing to children.

About one in 10 high school students has used an e-cigarette in the past month, according to the National Youth Tobacco Survey, released in November. And while e-cigarette use among teenagers has generally declined since 2019, flavoured, disposable devices, including Elf Bar, have been ascendant.

Elf Bar, which is also sold under the names EBDesign and EBCreate, hit US shelves in November 2021, according to The Associated Press. By this past summer, it had become the leading e-cigarette brand among middle- and high-school students who vape, according to the survey.

Visually similar products abound, including Flum Pebble, Juicy Bar, Air Bar Nex and Lost Mary.

Elf Bar has not been authorised for sale by the FDA, but the vapes are readily available in stores. The agency has directed shipments from China to be seized at the border.

The company that manufactures Elf Bar, IMiracle Shenzhen Technology, has argued that it is being unfairly targeted by the FDA and that its products, which carry a stark, black-and-white label warning that nicotine is addictive, are geared toward adult consumers.

Still, some see the physical design of the devices as a clear appeal to the visual sensibility of Gen Z.

“I would certainly argue that modern vapes, especially Elf Bars, are targeted more toward young Gen Z and even Gen Alpha,” said Mr Ben Varquez, managing director of YMC, a youth-marketing agency that does not work with clients in the tobacco industry.

Today’s young customers are less drawn to tech-y minimalism than to vibrant colour palettes and playful silhouettes that stand out on social media, he said. If Elf Bar was trying to design a product in line with Gen Z consumer tastes, he said, “they’ve absolutely nailed it”.

Some e-cigarettes are being packaged similarly to beauty, cosmetic and skin-care products that line the shelves at Sephora. Their pastel boxes are of a piece with upscale beverage brands like Kin Euphorics or the woozy gradients of Partiful, an event-invitation platform favoured by Gen Z.

“It’s this small, round cutesy thing with super bright colours that looks really friendly,” said Ms Taylor McGee, 26, a graphic designer in Brooklyn. “It’s positioned closer to these banal objects that aren’t bad for you.”

The FDA has greenlit some e-cigarettes in order to help adult smokers transition away from cigarettes. But it has banned the sale of most flavoured vapes, citing the risks of their appeal to young people.

Studies show that several factors encourage young people to try e-cigarettes, including exciting flavours and social pressure. And though there is limited research on how the physical appearance of the latest wave of e-cigarettes may attract young people, a British study published in 2023 reported that subjects aged 11 to 16 saw colourful, disposable e-cigarettes as “trendy”, “cool” and a “fashion accessory”.

That sets them apart from the earliest e-cigarettes, which were clunky modular systems or simple white “cig-a-likes” that mimicked the appearance of real cigarettes.

Then came Juul, a sleek, dark rectangle created by two graduates of Stanford’s design school and released in 2015. Minimal and discreet, it enabled young people to covertly vape in class or their school bathrooms.

Use of Juul exploded among teenagers around 2018 and 2019, drawing concern from parents and doctors about how vaping would affect young peoples’ health.

The company was accused of marketing to minors soon after the product hit the market. This spring, Juul Labs agreed to pay more than US$400 million (S$542 million) to settle claims that its advertising targeted adolescents.

Juul became “the poster child for all the ways the vaping industry went wrong”, said Ms Jamie Ducharme, author of Big Vape: The Incendiary Rise Of Juul and a health correspondent at Time magazine.

The device’s distinctive design – once a selling point – became associated with “flouting regulation and kicking off a scandal”.

Ms Ducharme speculated that newer e-cigarette companies probably wanted to distance themselves from the look of Juul.

“I’m not sure they went in the correct direction,” she said.

‘You want to show it off’

The bolder look of new, disposable e-cigarettes may correspond with a shift in some young people’s openness about vaping.

When Ms Karely Alcantara, 21, began vaping in high school, most of her friends used Juuls, which were easily concealed from teachers and family members.

Today, Ms Alcantara, now a student at the University of Maryland, sees people treating Elf Bars as ubiquitous accessories. She spots them at bars, in the cafeteria at her student centre, and on TikTok and Instagram.

“Nobody’s trying to hide it anymore, because everybody vapes,” Ms Alcantara said. She said she stopped vaping in 2022 with the help of a text-messaging program from Truth Initiative, a tobacco-control group. She is now a student ambassador for the initiative, a role for which she has received a stipend.

Not everyone is showing off their Elf Bars.

Ms Emma Longo, 22, a programme coordinator at a church who lives in Fishers, Indiana, said she started vaping because she thought it looked cool.

The devices are always on hand among her friends; there is always a new colour or flavour to try.

But seven years later, she hides the devices from family members. She relies on vaping to cope with stress, and worries about how it will affect her and her friends’ health in the long term.

Now, when she pictures a member of Gen Z, she said she pictures vaping.

“It’s become a part of the culture,” she said. “Now that I’m really thinking about it and processing it, that’s kind of scary.” NYTIMES