San Francisco has become the first city in North America to ban the use of traditional plastic grocery bags, a step that municipal leaders hope will spread across the country.

Passed Tuesday by the city's board of supervisors, thelaw prohibits large grocery stores and drugstores from using non-recyclable andnon-biodegradable plastic bags made from petroleum products.

Supermarkets will have six months to comply while drugstores willhave up to one year.

The city legislator who introduced the bill, Ross Mirkarimi, said that up to 200 million plastic bags are used each year in the city of roughly 740,000 people.

It's estimated a traditional plastic bag takes 1,000 years to dissolve.

"The first order of conservation is reduction and what we want to do is reduce the non-recyclable plastic bag," Mirkarimi said.

"Many [foreign] cities and nations have already implemented very similar legislation. It's astounding that San Francisco would be the first U.S. city to follow suit," he said.

Willreduce carbon dioxide output

Jared Blumenfeld, the head of the city'senvironment department, said there would be many benefits.

Bycutting 100 million plastic bagsa yearthe city willsave 1.5 million litres of oil, and eliminate 4.2 million kilograms of carbon dioxide, Blumenfeld said.

Blumenfeld said he hopes other cities will follow in San Francisco's footsteps.

"We certainly hope that it will proliferate throughout the United States, certainly at least throughout the state of California," he said.

Canadian town to ban bags

On April 2, the tiny town of Leaf Rapids in northwestern Manitoba is set to become the first Canadian community to ban plastic bags.

The bylaw prevents retailers from selling or distributing the single-use bags. Ignoring the ban could result in a $1,000-per-day fine.

Officials will hand out cloth shopping bags to each of the town's roughly 550 residents before the ban comes into effect on April 2.

The B.C. mountain town of Rossland is also considering a voluntary ban on single-use plastic bags.

With files from the Associated Press