SAN FRANCISCO (AP) — San Francisco supervisors moved a step closer Tuesday to becoming the first city in the U.S. to ban all sales of electronic cigarettes to crack down on youth vaping.

Supervisors unanimously approved a ban on the sale and distribution of e-cigarettes. They also endorsed a ban on manufacturing of e-cigarettes on city property. The measures will require a subsequent vote before becoming law.

“We spent the ’90s battling big tobacco, and now we see its new form in e-cigarettes,” Supervisor Shamann Walton said.

The supervisors acknowledged that the legislation would not entirely prevent youth vaping, but they hoped it would be a start.

“This is about thinking about the next generation of users and thinking about protecting the overall health and sending a message to the rest of the state and the country: Follow our lead,” Supervisor Ahsha Safaí said.

City Attorney Dennis Herrera said young people “have almost indiscriminate access to a product that shouldn’t even be on the market.” Because the Food and Drug Administration has not yet completed a study to assess the public health consequences of e-cigarettes and approved or rejected them, he said, “it’s, unfortunately, falling to states and localities to step into the breach.”

Most experts agree that e-cigarettes are less harmful than the paper-and-tobacco variety because they do not produce all the cancer-causing byproducts found in cigarette smoke. But researchers say they are only beginning to understand the risks of e-cigarettes, which they think may damage the lungs and blood vessels.

Since 2014, e-cigarettes have been the most commonly used tobacco product among young people in the country. Last year, 1 in 5 U.S. high school students reported vaping in the previous month, according to a government survey.

FDA spokesman Michael Felberbaum said in a statement that the agency will continue to fight e-cigarette use, including preventing youth access to the products, acting against manufacturers and retailers who illegally market or sell the products to minors and educating young people about health risks.

Leading San Francisco-based e-cigarette company Juul frames vaping as a healthier alternative to smoking tobacco. Juul has said it has taken steps to deter children from using its products. The company said in a statement that it has made its online age-verification process more robust and shut down its Instagram and Facebook accounts to try to discourage vaping by those under 21.

“But the prohibition of vapor products for all adults in San Francisco will not effectively address underage use and will leave cigarettes on shelves as the only choice for adult smokers, even though they kill 40,000 Californians every year,” Juul spokesman Ted Kwong said.

Tuesday’s vote also sets the stage for a November ballot fight over e-cigarettes. Juul has already contributed $500,000 to the Coalition for Reasonable Vaping Regulation, which is set to gather signatures to put an initiative on the issue before voters.

The American Vaping Association opposed San Francisco’s proposal as well, saying adult smokers deserve access to less hazardous alternatives.

“Going after youth is a step that you can take before taking these out of the hands of adults,” said the association’s president, Gregory Conley.

Groups representing small businesses also opposed the measures, which they said could force stores to close.

“We need to enforce the rules that we have in place already,” said Carlos Solórzano, CEO of the Hispanic Chamber of Commerce of San Francisco.

Walton said he would establish a working group to support small businesses and address their concerns.

Although San Francisco’s ban is unlike any other in the country, the Public Health Law Center at Mitchell Hamline School of Law reports that all but two states have at least one law restricting youth access to e-cigarettes. City voters last year approved a ban on sales of candy and fruit-flavored tobacco products.

Stanton Glantz, a professor of medicine at the University of California San Francisco Center for Tobacco Control and Research and a supporter of the measures, said e-cigarettes are associated with heart attacks, strokes and lung disease.

The presence of e-cigarettes, he said, has “completely reversed the progress we’ve made in youth smoking in the last few years.”