Lawmakers in a Long Island county have voted to approve what would be the nation's first ban on baby bottles and toddler sippy cups made with a chemical that some studies suggest may be harmful to infants.

The ban on Bisphenol-A (BPA) was approved unanimously by the Suffolk County Legislature on Tuesday. It will take effect if County Executive Steve Levy signs it, but he has not indicated whether he will do so.

The FDA had said last fall that BPA was safe, but after an independent report found deep flaws in its study the agency announced in December that it was planning more research.

Consumer advocates hailed the Suffolk County vote. Consumers Union said it was a first for the nation, though several states, including California, Oregon, Washington and Hawaii, are considering bans. Canada announced in October it was banning BPA in baby bottles.

"This is a victory for all consumers, but most of all for our youngest ones," said Dr. Urvashi Rangan, senior scientist and policy analyst for the Yonkers, N.Y., based group.

"This landmark legislation sets a new precedent and sends a strong message," Rangan said Wednesday.

Major U.S. retailers, including Toys 'R' Us Inc. and Wal-Mart, already have removed products containing BPA from their shelves because of the growing controversy.

BPA is in many plastics imprinted with the recycling number "7" and the letters "PC."

Concerns about the chemical stem from the fact that it can mimic estrogen, a powerful hormone. While the kidneys of mature children and adults quickly eliminate the chemical from their bodies, newborns and infants may retain it for longer periods. Babies can be exposed to BPA through infant formula packaging. Exposure could lead to developmental problems, proponents of the ban contend.

Steven Stern, the Suffolk County legislator who sponsored the ban, said the FDA review prompted him to act.

"We can't wait," Stern said in a telephone interview. "We don't know how long it's going to take. And we have a very proud tradition here in Suffolk County of being leaders on such important issues."

The county legislature was among the first to ban hand-held cell phones while driving, and to ban smoking in restaurants and public places. It enacted an early law requiring nickel deposits on beverage containers.

Suffolk's law calls for a $500 fine for retailers selling banned products; it doubles to $1,000 for a second offense.

Levy, the county executive, "is evaluating the legislation, and will wait to receive further input through public hearing before making a final decision," his spokesman Mark Smith said.

The North American Metal Packaging Alliance said Wednesday that it was disappointed by the legislature's vote. A representative of the group told the lawmakers on Tuesday that a ban would have a significant adverse impact on consumers' ability to obtain baby foods and bottles.