San Francisco's ban on electronic cigarettes is an "insane public policy," some public health experts say, arguing that the city should ban all tobacco products instead.

The criticism came after San Francisco on Tuesday became the first major city in the United States to ban e-cigarettes. The ban, which will go into effect 30 days after the mayor signs the ordinance, was approved by city supervisors who cited the "growing health epidemic of youth vaping" in their decision.

E-cigarette use has undeniably soared among youth, alarming public health officials: 20.8 percent of high school students reported in 2018 that they had used the vaping devices within the past 30 days, compared to 1.5 percent in 2011, according to the Centers for Disease Control and Prevention.

The CDC says e-cigarettes are not safe for children and teens, but adds that they have "potential to benefit adult smokers who are not pregnant if used as a complete substitute for regular cigarettes and other smoked tobacco products."

Still, the long-term effects of vaping devices are unknown, particularly on youth who smoke them. They contain the addictive substance nicotine but far fewer of the toxins that combustible cigarettes have.

While e-cigarettes are generally understood to be less harmful than cigarettes or cigars, many parents, school administrators and pediatricians have expressed concern that the way e-cigarettes deliver nicotine is negatively affecting the development of teens' brains, particularly because they can deliver a higher dose more quickly than traditional cigarettes can.

But some public health experts feel banning them altogether like San Francisco alienates an entire population of adult cigarette smokers who are trying to quit and need an alternative.

"We're taking the risk of addiction among kids," said Kenneth Warner, a professor emeritus at the University of Michigan of Public Health, "and comparing that with the immediate danger of smoking-related illness and death in smokers who have not been able to quit otherwise and who might be able to quit with vaping."

Warner cited a New England Journal of Medicine study from January 2019 that found among smokers in a smoking cessation clinic trying to quit traditional cigarettes, nearly double the number of people — 18 percent versus 9.9 percent — who used vaping over nicotine-replacement products such as gum or patches were able to quit. Other studies have concluded there isn't enough evidence yet to say whether e-cigarettes are an effective long-term aid to quit smoking.

"If the board of supervisors were interested in public health, they would prohibit the sale of cigarettes in San Francisco."

"If the board of supervisors were interested in public health, they would prohibit the sale of cigarettes in San Francisco. That's a far higher priority than banning vaping from a public health point of view," he said. "There really is an irony that now you can buy your marijuana and your cigarettes, but you won't be able to get vaping products, which are certainly far less dangerous than cigarette smoking. It's ludicrous."

He added that in addition to banning tobacco, San Francisco should make efforts to educate teens about the possible health effects of e-cigarettes.

Dr. Michael Siegel, a professor at Boston University School of Public Health whose research focuses on tobacco reduction, called the ban an "insane public policy."

"It makes it easier to get cigarettes than e-cigarettes," Siegel said. "I fear it really sends a bad message to other cities and to youth. It basically says we think vaping is worse than smoking."

"The worst part of this, beyond the fact that it makes no sense from a public health perspective, is I think it's actually going to do public health harm," he continued. "By taking e-cigarettes off the shelves, you're basically going to force a lot of ex-smokers to go back to smoking."

San Francisco's e-cigarette ban comes on top of a 2014 ordinance that banned the sale of e-cigarettes where traditional tobacco products are already prohibited, which includes within 500 feet of any schools.

Siegel suggested further limiting access to e-cigarettes by only selling them in stores that are age-restricted where customers are always carded — like liquor stores do.

Dr. Neal Benowitz, a professor of medicine at the University of California, San Francisco, and a leading expert on nicotine, agreed.

"The risks of e-cigarettes kids are using now are unknown and of concern. But to me, the logical thing would be to focus more on restricting youth access to these devices," he said. "If they wanted to get them out of gas stations and grocery stores, that's fine, but I think e-cigarettes should have remained available in places like tobacco shops and online access, where there's verification of age."

The San Francisco board of supervisors' measure said e-cigarettes posed "significant public health consequence" to minors. The board did not respond to multiple calls or emails for comment from NBC News regarding whether it would consider banning tobacco products.

In the past, vape manufacturers, such as JUUL, which is based in San Francisco, have come under fire for not only allowing underage access to its devices, but also for marketing in ways that may appeal to youth, with glossy social media posts and candy-like flavors for its nicotine pods. JUUL says it has since shut down its Facebook and Instagram accounts and strengthened its online age-verification system.

But some say that is not enough to stem the epidemic. Many states have moved to stamp out teen vaping, with at least a dozen raising the tobacco and vaping device purchase age to 21, including California.