Officials could make San Francisco the largest city in the United States to start banning residents from smoking cannabis and tobacco inside apartment and condo buildings due to the threat of secondhand smoking.

On Tuesday, the city’s Board of Supervisors are expected to cast their votes on a proposal that would ban smoking in an attempt to protect non-smoking residents. The act is already illegal in public areas such as stairwells and hallways, while some landlords implement a no-smoking rule more broadly indoors.

Supervisor Normal Yee proposed the idea and would extend existing laws and ban all residents from smoking inside buildings with at least three units, except for those that need the substance for medical reasons. The order would also affect private buildings, low-income buildings, and condominiums.

The law would fine repeat offenders with up to $1,000 per day of continued violation but would not be evicted due to infractions. Several cannabis activists have criticized the new law saying it goes against their right to use a legal substance if they did not have enough money to purchase their own homes.

Under state law, residents are not able to smoke cannabis in public areas, but it is not strictly enforced in San Francisco. Supporters of the ban said the regulation is crucial in keeping non-smokers healthy, especially those who live in low-income apartment buildings.

Yee said, “My motivation is just to give people clean air to breathe, that’s all,” as he is set to leave his position in January. The official’s proposal, if passed, would bring San Francisco in line with 63 other cities in California that bans smoking.

The city has placed the responsibility of enforcing the new law on the Department of Public Health. Yee said San Francisco first aims to educate violators and prioritizes in helping smokers quit their vice.

The American Heart Association’s Bay Area division expressed its support for the proposal and said it was an “important strategy to protect vulnerable populations from dangerous secondhand smoke exposure in their homes.” The city’s Tobacco-Free Coalition said the ordinance would help residents increase their health equity.

Co-sponsors of the proposal include supervisors Shmann Walton and Sandra Lee Fewer. Supervisor Rafael Mandelman planned to put an amendment to the law that would exclude cannabis from its list of banned substances. While Mandelman agreed to the dangers of smoking tobacco, he said people smoking cannabis at home should be allowed to continue.

The Board of Supervisors-appointed Cannabis Oversight Committee strongly disagreed with the ban. The group sent an extensive letter to the board which wrote that city officials proposed the ordinance to protect non-smokers at the cost of the rights of cannabis users, the San Francisco Chronicle reported.

The chair of the committee, Nina Parks, said, “The ordinance would disallow smoking, but only for people in multiunit residential buildings, meaning that San Franciscans who can afford to buy freestanding homes would be unaffected and could still smoke in peace.”

Parks said that exempting people who have medical cannabis cards was pointless due to smoking the substance being legal in the city. She added that the hefty fine was unnecessary because those who could pay the fine could afford freestanding homes, making them exempt from the law.

The co-president of the Harvey Milk LGBTQ Democratic Club, Kaylah Williams, considered the law having a disproportionate impact on lower-income residents and people of color who are generally residing in denser areas within the city. Statistics showed that 53% of city residents live in buildings with two or more housing units.

Williams expressed her frustrations with the ordinance and said it would result in a lot of classist issues and problems.