Customers would no longer have plastic bags as an option. They would need to bring in their own reusable bag or they could purchase a paper one for 10 cents. That's to pay the store for the cost of the bag.
The measure, which will come back for a final vote when exact language is finalized, was approved on a 3-1 vote.
Large stores have until July 1, 2011 to comply. Smaller stores have until Jan. 1, 2012.
"It's a historical day because L.A. County will be the largest municipality in California to ban single-use plastic bags," said state Assemblywoman Julia Brownley (D-Santa Monica). "And then we're going to go back to Sacramento because this ordinance mimics exactly the bill that I carried in Sacramento."
"It's too bad that we couldn't pass it in the state, but L.A. can lead the way for other cities in California," said Angela Howe, a Surfrider Foundation representative. "San Francisco has already done it. Santa Monica has already done it. Manhattan Beach has already done it."
Opponents say it amounts to yet another fee for consumers who will have to purchase re-usable bags for about $1 apiece, or a dime apiece for paper bags at grocery stores.
"I'm opposed to charging people, where there's a plan to charge people 10 cents per bag," said Charles Brister, Unite US. "That's going to hurt the low-income people the most."
"This is exactly why approval ratings for lawmakers are so dismal," said Sherri McCarthy, an American Chemistry Council representative. "Voters sent a clear message, a clear signal, that they want final approval of any new fees. And this decision flies in the face of those voters of California. This is a terrible policy precedent, charging consumers fees on bags and allowing grocers to keep those profits instead of protecting the environment."
The county ordinance is similar to a bill that California lawmakers rejected in August. That would've been the first statewide ban on the use of plastic shopping bags.
Some shoppers said plastic bags are wasteful.
"It's just bad for the environment, and I think it's a great idea," said Oscar Cruz.
"I feel that I'm doing my part with it by bringing my own stuff. I shop here every day, so it would be a lot of plastic bags I'd be using if I didn't. I feel like I'm doing a good thing," said shopper David Bullen.
Before the voting took place, a public hearing was held so that residents could have their say on the issue.
County officials are hoping the nearly 90 cities in the county will adopt the ordinance that has become law in unincorporated L.A. County.
The law only affects residents in unincorporated Los Angeles County. It does not affect residents of the city of L.A. or the rest of the county.
City News Service contributed to this report.