SAN FRANCISCO >> Supervisors in famously pot-friendly San Francisco are under pressure from cannabis advocates to pass regulations that would allow the industry to flourish once recreational sales become legal throughout California in January.

The San Francisco Board of Supervisors is scheduled to take up proposed regulations today, when they may vote on a stop-gap measure to allow the sale of recreational cannabis through existing medical marijuana outlets on Jan. 1. That would give them time to figure out where to allow new stores.

But California state senator Scott Wiener, a Democrat and former supervisor from San Francisco, urged against the measure, saying it would stifle competition.

He issued a stinging statement with former supervisor David Campos, who is now chair of the city’s Democratic Party, Tuesday saying the board is bowing to anti-cannabis pressure and “getting dangerously close to destroying” an industry embraced by most of the city.

It’s been surprisingly difficult to write local cannabis rules as critics, many of them older Chinese immigrants who oppose marijuana use, try to restrict where pot can be sold in a city that celebrates the 4/20 marijuana holiday with a group smoke-out on Hippie Hill.

The possibility of overly strict regulations has businesses fretting over access and some San Franciscans wondering what happened to the counter-culture, anti-Prohibition city they know and love. The smell of cannabis being smoked is not uncommon in certain neighborhoods and parks.

“Let’s be honest: Cannabis is effectively legal now and the sky hasn’t fallen. A lot of the information people have been given is completely false,” said Supervisor Jeff Sheehy, who uses medical marijuana to mitigate pain from older HIV medications.

Cannabis advocates prefer a 600-foot buffer from schools, comparable to the radius required of stores that sell liquor or tobacco.

But some Chinese-American organizations have pushed back, calling for an outright prohibition on retail stores in San Francisco’s Chinatown. They want future retail stores to be at least 1,500 feet away from schools, child-care centers and any other place minors gather.

Ellen Lee, family social worker at the nonprofit San Francisco Community Empowerment Center, which has helped lead the protests, said most of the people opposed to recreational cannabis are elderly and speak little to no English. She said children are impressionable and must be protected from a drug that remains illegal under federal law, and she is frustrated by elected officials.

“We have been meeting with them and talking to them,” she said, “but they are not listening.”

Chinese-Americans are an integral part of San Francisco’s history and they carry political clout in a city where one-third of its 850,000 residents are Asian and Chinese-Americans are the largest Asian sub-group. The mayor is Chinese-American, as are other elected officials in the city.