Updated

A state advisory board on Monday called for a study to determine if sodas and energy drinks containing caffeine pose a risk to pregnant women.

The review could lead to warning labels on the drinks under Proposition 65, a 1986 ballot measure that requires the state to identify chemicals that could cause cancer or birth defects.

"If I were a pregnant woman or a woman thinking about being pregnant, I would want to know, should I be avoiding caffeine?" said Renee Sharp, a senior analyst with the Environmental Working Group, an environmental research organization that's based in Washington D.C. "It's a really important question, and I think people are looking for answers."

The advisory panel, the Science Advisory Board Developmental and Reproductive Toxicant Identification Committee, also requested an immediate review of Bisphenol-A, which could lead to warning labels on plastic baby bottles, water bottles and reusable food containers. The chemical Bisphenol-A has been shown to affect hormonal levels.

It was unclear Monday whether the state would follow the board's advice.

"This is a nonbinding recommendation; however, we will give it heavy weight because this is a panel of scientific experts," said Sam Delson, spokesman at the Office of Environmental Health Hazard Assessment.

If the office agrees to conduct the reviews, it would hold public hearings and do a more extensive review of existing research over the next year, Delson said. The board would then decide whether to require warning labels on caffeine and Bisphenol-A products similar to labels now used on potato chips and alcohol.

The board's 4-3 vote calling for the caffeine study was part of a two-year review of 286 chemicals that state officials said might warrant speedy review under proposition 65. Caffeine and Bisphenol-A were among eight chemicals selected for the board's consideration.

In arguing for the caffeine review, board member Hillary Klonoff-Cohen said dozens of scientific studies have linked the stimulant to miscarriages, premature births and low birth weight. The evidence is more prevalent in animal studies.

The label requirement would not cover coffee and tea, which have much higher caffeine levels, because the stimulant occurs naturally in those beverages. Proposition 65 only applies to chemicals that are added to foods or products.

The distinction drew criticism from the American Beverage Association, which said the coffee exemption would confuse consumers and unfairly penalize the soft drink industry.

"To provide a Proposition 65 warning on soft drinks would communicate to women that moderate amounts of caffeine is not safe," said Gary Roberts, a Los Angeles attorney representing the beverage association.

A University of Southern California study that was commissioned by the American Beverage Association concluded that warning labels on soft drinks led women to falsely believe there is more caffeine in soda than coffee.

The College of Obstetricians and Gynecologists, the March of Dimes, the Mayo Clinic and other health organizations have said that moderate amounts of caffeine _ about two cups of coffee a day or seven soft drinks a day _ are safe for pregnant women.