Federal health officials on Thursday authorized sales of the best-selling e-cigarette in the U.S., Vuse Alto, allowing manufacturer Reynolds American to keep the vaping brand on the market for years to come.

The Food and Drug Administration decision only applies to several tobacco-flavored versions of the reusable product, which takes cartridges filled with liquid nicotine. The FDA previously rejected Reynold’s application for its more popular menthol flavor, but the company is challenging that decision in court.

Last month, the FDA granted competitor Njoy the first authorization for a menthol-flavored e-cigarette. The vaping brand, which is not a big seller, is controlled by tobacco giant Altria, which also sells Marlboro cigarettes.

Thursday's announcement is not an approval or endorsement, and the FDA reiterated that people who do not smoke should not use Vuse or any other e-cigarettes. The FDA determination indicates that smokers who switch completely to Vuse can reduce their exposure to deadly carcinogens and other chemicals found in traditional tobacco.

“All tobacco products are harmful and potentially addictive,” the FDA said in a statement. “Those who do not use tobacco products, especially young people, should not start.”

Like other tobacco companies, Reynolds makes most of its income from traditional cigarettes, including Camels and Newports.

Vuse made up 40% of U.S. vaping sales in the past year, according to retail data from Nielsen. Most company sales are for menthol products, which remain available under a court order while Reynold’s challenges the FDA's negative ruling.

Juul Labs is now a distant second in the e-cigarettes market, accounting for less than a quarter of retail sales. The company was forced to drastically cut back its marketing and promotions following legal settlements with states, local governments and families that blamed the brand’s small, discreet e-cigarettes for hooking children on nicotine.

The FDA is wrapping up a sweeping regulatory review intended to clean up the multibillion-dollar vaping industry after years of delays.

Some brands like Vuse have been sold in the U.S. for years, awaiting FDA action on their scientific applications. The market also includes thousands of fruit- and candy-flavored products from China that are technically illegal but widely available in convenience stores and vape shops.

The FDA faced a self-imposed court deadline last month to wrap up its yearslong review of major vaping brands. Currently, Juul's products remain under federal review, although FDA recently rescinded a 2022 order that would have forced the products off the market. That action never took effect because FDA regulators agreed to place it on hold following a legal challenge by Juul.

The agency has rejected more than 26 million applications for products it received from vaping companies hoping to stay on the market. Only a handful of products from major manufacturers have been authorized to help smokers

To win FDA authorization, companies generally must show that their e-cigarettes provide an overall health benefit for smokers, without significantly appealing to kids.