This environmentally friendly city put a green spin Tuesday on the checkout question "Paper or plastic?," becoming the first in the nation to outlaw non-recyclable plastic bags from use in supermarkets, drugstores and other large retailers.

By a 10-1 vote, the Board of Supervisors required the use of compostable or recyclable bags — a move officials predicted could soon be imitated by other cities nationwide. One supervisor voted against the ban, saying the issue needed more study.

Each year businesses here dispense an estimated 180 million plastic bags, killing marine life and clogging landfills, said Supervisor Ross Mirkarimi.

The Plastic Bag Reduction Ordinance, written by Mirkarimi and co-sponsored by six other supervisors, gives major supermarket chains with more than $2 million in annual sales six months to make the switch to biodegradable bags. Pharmacies and retailers with at least five locations have one year. Violators face fines of up to $500.

At a news conference before the bill's passage, Mirkarimi handed out canvas shopping bags that read "SF Environment: Our Home. Our City. Our Planet." The new law calls for bags that are reusable or made of recyclable paper or plastic that can be composted.

"We can take steps to make our economy a little more soulful in San Francisco," Mirkarimi told the crowd in front of City Hall. "We can't sleepwalk into the future. The end of the era of cheap oil is here."