The Board of Supervisors unanimously approved a measure raising the legal age to purchase tobacco products within San Francisco from 18 to 21 years old.

The ordinance is scheduled to go into effect on June 1. Tobacco sellers would be given a one-year grace period during which they will be reminded of the law via notices from the Department of Public Health. Those caught selling to people under the legal age during the time period would get a warning. After that year, the offenders could have their license to sell tobacco suspended or revoked.

San Francisco now joins more than 100 U.S. cities like Boston and New York City that have similar ordinances in place. Last year, Hawaii became the first state to increase the purchase age. The new minimum age limitation also includes e-cigarettes, which are classified as cigarettes under San Francisco municipal code.

The legislation was created by Supervisor Scott Wiener, who believes that raising the minimum age would prevent young adults from smoking, which could potentially save lives and reduce healthcare costs.

“For too long, we have seen the horrible effects that tobacco use has on our residents and particularly our young people,” Wiener said in a press release. “Passage of this legislation shows, once again, that San Francisco is a leader on progressive public health policy and that we are committed to reducing tobacco use in our city.”

A study released by UC San Francisco revealed that in 2009 the city spent $380 million in healthcare costs related to tobacco use.

Wiener also hopes that the legislation will help push a proposal to change the tobacco-buying age statewide, which failed to gain traction last fall.

“It’s a good idea, health-wise,” said 19-year-old art major Shea O’Sullivan, “But I don’t know how well it’ll work.”

Smoking has become a hot button issue again in the U.S. after the popularity of e-cigarettes skyrocketed in recent years. According to a 2015 document released by the American Academy of Pediatrics, in 2014 more teenagers used e-cigarettes than all forms of tobacco products.

Many students are upset with news of the legislation passing.

“It makes sense,” said 22-year-old art major Julian Ramos, “But as someone that’s been smoking since I was 18, I think it’s bullshit.”

“I feel it’s unfair, because being 18, you’re allowed to vote and you’re allowed to join the army,” said business major Russell Holguin. “You’re supposed to be allowed to do what you want so long as it’s your choice.” Holguin, who is 18, said that while he disagrees with the new limitation, he plans to abide by it.

Current California regulations set the minimum age at 18 and has the power to reject city and county decisions to increase the age requirement. The National Association of Tobacco Outlets argues that state law cannot be superseded.

Healdsburg, California suspended enforcement of its age limit ordinance after the tobacco association threatened to sue. Santa Clara County is still enforcing its tobacco ban for people under 21.

It is unclear how San Francisco’s smoking law will affect medicinal marijuana. California residents who are 18 and older can get medical marijuana from a licensed doctor and buy and possess up to half a pound of marijuana. The issue could be complicated further by a full marijuana legalization initiative that is striving to make it to the 2016 ballot.

Still, there is doubt that the legislation will be effective.

“Kids are going to find a way to buy stuff,” said Holguin. “Not just cigarettes, but alcohol and stuff like that too. Kids always find a way.”