Nail salons and beauty magazines are buzzing about gel manicures. Customers love them because they dry almost instantly, shine like patent leather and don’t chip for two weeks. Salons get to charge more than double the price of a traditional manicure and then have repeat business when the customer returns to have the polish removed.

But gel manicure clients must sit with their hands under ultraviolet lamps for up to 10 minutes to cure, or dry, the polish. Those minutes under the bluish-purple light might make you wonder: Is this safe?

A 2009 article in a medical journal looked at two cases of women who reported repeated exposure to UV nail lamps and developed skin cancer on the backs of their hands. (The lamps are also used to set acrylic nails and dry traditional manicures and pedicures, but in about half the time.)

“Artificial UV light does elevate your risk for developing skin cancer” and for premature aging of the skin, says Anna M. Bender, a dermatologist at Johns Hopkins University. “So people could use a sunscreen to try to block the UV from their surrounding skin.”

People should reach for a sunblock that contains zinc or titanium oxide rather than a typical sunscreen. Those ingredients shield the skin from UVA rays (the kind emitted by nail lamps), whereas many sunscreens protect only against UVB light. Even broad-spectrum lotions may not cover the full UVA spectrum, Bender says.

Halting a manicure to slather on sunblock would be highly unusual behavior, according to Lonnie Nguyen, owner of Cleveland Park Day Spa and Toe Tally Nails in the District. Not one of her clients at either business has ever stopped the procedure to apply sunblock for UV protection.

In fact, the only concern her customers have shown about gel manicures is smudging.

“They still ask, ‘Can I touch?’ ” Nguyen says. “The second time, they know” that their nails are completely dry and hard by the end of the manicure, she says. Traditional nail polish can take more than an hour to harden, and anyone who has gotten a manicure or pedicure knows the drawbacks: gingerly reaching for credit cards and walking home in flip-flops, no matter the weather.

Gel manicures have been around for about a decade but took off in popularity only with the 2010 launch of CND’s Shellac brand, according to Nguyen and others. The original gel manicure consisted of a thick overlay that was difficult to remove: Even after soaking the fingertips in acetone, nail technicians would often have to scrape away the gel, potentially damaging the nail. Shellac, on the other hand, is “more like amped-up nail polish,” says company co-founder Jan Arnold. Such products as OPI’s GelColor have followed.

Customers return to the salon for removal once the polish has chipped or the nails grow out too far. They can try to remove them at home using acetone nail polish remover, but doing so will probably require scraping. (Salons usually use acetone-soaked cotton pads inside Band-Aidlike wraps for removal; this technique allows the polish to slide off more easily.)

Nguyen says that about 60 percent of her manicuring business is now Shellac and GelColor, and she says they have beefed up her business. A regular manicure costs $14 at her salon; Shellac is $35. Removal is free if you get a new gel manicure and $5 if you don’t. Gel pedicures aren’t as popular because traditional pedicures don’t chip as quickly as manicures do.

Nail salons brought in nearly $1.9 billion in 2010, according to U.S. Census Bureau figures. Health issues related to nail salons are well documented in medical literature; they include fungus, boils, rashes and allergic reactions to acrylic nails.

Gel manicures are not the first use of UV lights in nail salons. At Cleveland Park Day Spa, for instance, customers getting standard manicures have sat with their hands and feet under the bluish-purple glow for years because Nguyen uses a top coat that requires about three minutes of UV light to dry it, half to a third of what a gel manicure would take.

Arnold says her product is safe, citing research done by CND’s scientific consultants.

The Food and Drug Administration regulates UV nail lamps as radiation-emitting electronic products, a category that includes microwave ovens, mammogram machines and airport-security X-ray devices. The FDA has released no statements about UV nail lamps, but it offers extensive resources online for consumers about the risks of using UV lights for indoor tanning, which generally calls for a much longer exposure than that required for nails.

Arnold says it is be unfair to draw conclusions about UV nail lamps based on studies of tanning beds because of the differences in time used and bulb strength. “There’s no comparison to tanning beds,” she says.

The 2009 article, which appeared in the Archives of Dermatology, however, stated that, considering the difference in the amount of body surface being treated by tanning beds and nail lamps, the UV radiation being received is “approximately comparable.”

That article, by dermatologists at the M.D. Anderson Cancer Center in Houston and the University of Texas Medical School, reported on two otherwise healthy middle-aged women who developed non-melanoma skin cancers on their hands. One got her acrylic nails done twice a month for 15 years using UV lamps; the other had skin cancers develop after having had eight UV nail lamp exposures to her hands in one year.

Although the authors said “no strong conclusion” can be drawn from such a small sampling, they added, “It appears that exposure to UV nail lights is a risk factor for the development of skin cancer; however, this observation warrants further investigation.” They suggested that doctors pay particular attention to the backs of hands and feet when looking for skin cancer in women who get frequent manicures and pedicures.

CND’s chief scientific advisor, Doug Schoon, a chemist who has worked as a consultant to the beauty industry for more than 30 years, says the article’s linking of nail lights to tanning beds is flawed. His calculations show that the UV rays from nail lamps are the equivalent to one or two minutes in the sun each day between manicures. Clients can see the difference between the devices themselves: Hands don’t get tan during manicures.

“No one should run screaming from the salon thinking they’re going to get skin cancer,” Schoon says. “Getting a Shellac manicure is a very, very low-risk behavior.”

Irene Alexiu, a 25-year-old from Arlington, clearly agrees. She works with her hands a lot for her retail job, and her nails still looked perfect two weeks after a recent gel manicure. She was not concerned about health risks.

“When you get a normal manicure they use the UV light,” she says. “You just do it more time with Shellac.”

Saslow, a former Washington Post staff writer, is a freelancer writer specializing in health issues.