The city of San Francisco took a step toward banning plastic shopping bags on Tuesday, weeks after it banned Styrofoam food containers--both of which were popularized in post-war America for being sanitary.

"Under the legislation, which passed 10-1 in the first of two votes, large markets and pharmacies will have the option of using compostable bags made of corn starch or bags made of recyclable paper," the San Francisco Chronicle reports. "San Francisco will join a number of countries, such as Ireland, that already have outlawed plastic bags or have levied a tax on them. Final passage of the legislation is expected at the board's next scheduled meeting, and the mayor is expected to sign it."

The motivation for banning plastic bags, according to city officials, is environmental. Bags do not biodegrade, meaning they clog landfills. They also pose a threat to marine life, officials say. Businesses are expected to replace plastic bags with paper bags and other compostable alternatives. Small businesses are exempted from the ordinance.

What do you think? Is the San Francisco ban totally out of line, or groundbreaking environmental policy? Does your business use plastic bags? If so, do you feel guilty or not at all? Do you think that by serving ecological interests, there's a risk of turning the clock back on sanitary conditions? And if you have discontinued the use of plastic bags, what alternatives do you now rely on?