That may soon be the only question heard at grocery counters across San Francisco, as the city’s Board of Supervisors cast a decisive blow in the paper versus plastic debate on Tuesday, banning non-biodegradable plastic bags in its large grocery stores and pharmacies.

The ordinance, believed to be the first of its kind in the nation, will remove standard plastic bags from supermarkets and pharmacies with sales of more than $2 million a year, said its author, Supervisor Ross Mirkarimi, who said his city was simply following a worldwide trend toward greener grocers.

“Scores of nations have already gone through this,” said Mr. Mirkarimi, citing similar laws in places including South Africa and Taiwan. “It’s really astounding the United States would be so late in the game to come online to do something that should be common sense.”

Indeed, in a famously liberal city where finding the moral high ground can take a lot of climbing, the plastic bag has been something of the perfect villain for San Francisco politicians, a combination of common litter and nascent environmental scourge, linked to issues like global warming and big oil hegemony.

Most plastic grocery bags are made from polyethylene, which is derived from oil, which is considered by many San Franciscans to be the root of most of the world’s problems, from $4 gallons of gasoline to the war in Iraq. Opening statements by the law’s supporters at a committee meeting this month mentioned everything from the Kyoto Protocol (the 1997 environmental treaty that the United States refused to sign) to weapons of mass destruction (which are famously hard to store, or sack, properly).

“Frankly, this is our measured response to an obvious problem that global warming is not going away soon, and the era of cheap oil has come to an end,” said Mr. Mirkarimi, who estimated that San Franciscans used nearly 200 million non-biodegradable plastic bags a year. That number translates into about 450,000 gallons of oil, he said, and 1,400 tons of landfill trash. (Not buried here, of course; the city’s trash is taken to landfills outside the city limits.)

San Francisco already has one of the most ambitious recycling plans in the country, with a dozen categories of reclaimable trash and a tri-colored curbside program, including one bin for composting of food scraps and yard trimmings, another citywide innovation. The city also has a goal of having “zero waste” — i.e., everything is recyclable — by 2020.

The ordinance, which takes effect for grocers in six months, will allow food stores and pharmacies to use biodegradable plastic bags. But opponents say that those bags, which cost more to produce and buy, would simply increase costs for grocers, who already operate on a thin profit margin.

Dave Heylen, a spokesman for the California Grocers Association, a trade group that represents 6,000 supermarkets in the state, said his members were disappointed by the law and a little leery of the quality of new bags.

“There’s some real concern about the availability and integrity of the bags, meaning will it be able to hold the same amount of these items,” Mr. Heylen said. “And if it doesn’t, does it mean you’re going to be putting more bags into the system?”

Instead of legislation, he said, his group supports more efficient recycling and better education, including teaching “courtesy clerks” (a k a baggers) to “make smarter choices” when sacking. Which will not be easy when they are limited to paper bags, Mr. Heylen said. “It’s not as convenient,” he said. “You typically don’t have the same range of bags that you typically do with plastic.”

Supervisor Ed Jew, who cast the only “no” vote on Tuesday, said he feared the extra cost of degradable bags was likely to be passed on to consumers, who already labor in an expensive city where a trip to the market can rival a trip to Disneyland. “It’s a regressive tax,” Mr. Jew said. “And I think we’ve got larger issues here in the city to address.”

Mr. Mirkarimi said he did not necessarily dislike plastics, just what they were made from. “We’re not banning plastic, we’re just banning the content of the plastic so we can compost it,” he said. “Sometimes I use plastic bags. Sometimes I use paper. And sometimes, I bring a canvas bag from home.”

(By Jesse McKinley, NYT, 28/03/2007)