Tire manufacturers and retailers have agreed to phase-out the use of lead wheel weights, the U.S. Environmental Protection Agency said Friday.

Partners in the EPA's National Lead-Free Wheel Weight Initiative have agreed to phase-in the use of lead-free alternative wheel weights and reduce the amount of lead released into the environment by 2011.

"Our partners have pledged to reduce or eliminate their use of lead wheel weights," Susan Parker Bodine, assistant administrator of EPA's Office of Solid Waste and Emergency Response, said in a statement. "Their efforts will remove millions of pounds of lead from the environment and the waste stream."

The agency estimates 50 million pounds of lead are used each year for wheel weights in cars and light trucks. The wheel weights tend to come off when a vehicle hits a pothole in the road or stops suddenly, the EPA said.