SAN FRANCISCO >> San Francisco supervisors approved legislation that requires employers to provide new mothers a clean and private space to pump their milk, adding to the board’s long history of trying to make the city more equitable for workers even if that means more regulations for employers.

California and federal law already require employers to make reasonable efforts to provide lactation breaks. But advocates say the ordinance approved unanimously by the San Francisco Board of Supervisors today is significant because it spells out the kind of space required and mandates worker protections.

San Francisco Supervisor Katy Tang called her proposal the strongest lactation policy in the nation.

The lactation area must be clean, contain a chair and surface space for a pump, and have access to electricity. The legislation also specifies lactation rooms for new work spaces going forward, and it requires employers to distribute its lactation accommodation policy to all employees upon hiring.

The lactation legislation is the latest in a city that has championed worker rights. San Francisco supervisors in 2016 were the first to mandate private businesses provide fully paid leave to new parents. In 2014, San Francisco approved a $15 hourly minimum wage for workers, years before it became a mandate for the entire state.

“We’re talking about something that is so basic, it’s almost sad we have to legislate it,” said Julia Parish, an attorney at Legal Aid at Work, which worked with Tang’s office. “This is about working moms providing food for their babies.”

Dee Dee Workman, vice president of public policy at the San Francisco Chamber of Commerce, said she regularly hears from employers who say the city issues too many mandates.

But she said the chamber worked with Tang’s office to make this piece of legislation less onerous.

The legislation, for example, does not require employers to build a room or give up retail or dining space to accommodate employees. A screened-off area of a manager’s office will suffice if that is the only private space available.

“Especially for small businesses that struggle to hire in San Francisco, they’re looking for good, stable, happy employees,” Workman said. “And if somebody needs the accommodation, they do their best to accommodate them.”

Supervisors are required to vote again on the measure next week. It is expected to pass.

The law becomes operative Jan. 1.