Citing trash in the ocean, long-lasting litter in the streets and even carcinogenic properties, San Francisco has banned most Styrofoam.

The City by the Bay's board of supervisors voted on June 28 to no longer allow the plastic compound — polystyrene is its chemical name, Styrofoam is the popular brand — in food ware, packing materials, pool toys and more. The move could have implications for many city programs, not the least of which is recycling.

The city, which boasts an 80 percent diversion of trash from landfills, recognized with the vote that polystyrene can’t be recycled and doesn’t decompose well, making it a tough customer in its goal to get to zero waste.

The legislation also acknowledged that Styrofoam tends to find its way into local waterways — an especially large concern for San Francisco, which sits on the edge of a peninsula that marks the gateway into a mostly enclosed bay.

“The Bay Area Stormwater Management Agencies Association and Caltrans found that between 8 to 15 [percent] of plastics in San Francisco storm drains are polystyrene foam,” the ordinance reads. “The San Francisco Estuary Institute found that 8 percent of the microplastics entering San Francisco Bay from wastewater treatment facilities are polystyrene foam.”

The legislation also pointed out that research has linked the material to cancer.

Polystyrene has actually been featured in some high-profile environmentalist concepts. For example, Mark Jacobson, director of Stanford University’s Atmosphere/Energy Program, has spoken to media about his solar-powered house that features polystyrene in its insulation. People have demonstrated setups that use polystyrene to help buildings float, a concept the San Francisco planning group SPUR has examined as a possible solution to help cope with rising sea levels in the future.

But the ordinance doesn’t actually prohibit all polystyrene — materials that are packaged in the stuff outside the city-county and then shipped in are fine, as are certain specific uses. The ban applies more to things like coolers, packing peanuts, egg cartons and meat trays. Nonetheless, London Breed, president of the board of supervisors, calls the ban the toughest in the nation.

“The science is clear: This stuff is an environmental and public health pollutant, and we have to reduce its use,” she said in a press release. “There are ample cost-effective alternatives to Styrofoam on the market.”

The law also goes a little further than polystyrene, prohibiting any packing materials that can’t be recycled or composted. According to Breed, something like 100 cities across the nation have enacted some kind of partial ban on polystyrene, but none have gone so far as San Francisco.

Enacting far-reaching green initiatives is something San Francisco does a lot. Aside from Styrofoam, the city has also mandated rooftop solar panels on certain kinds of new construction, paved the way for onsite water treatment systems that recycle grey and black water, and is playing host to a demonstration project where several groups plan to make a low-income apartment building produce as much energy as it uses.