The California Legislature is considering Assembly Bill 319, which would ban products intended for use by children if made from plastics containing certain chemicals, including bisphenol A. The bill's proponents cite a scientifically unorthodox hypothesis that tiny exposures to bisphenol A -- far below those widely considered safe -- might harm health.

Everyone wants to protect the health of children, but this bill is unnecessary, scientifically unsupportable and counterproductive in that many of the targeted products enhance the health and safety of children and adults. Its passage would trigger needless fear in parents and others who use these products. In truth, years of scientific research around the world clearly demonstrates that the many important products made with bisphenol A are safe for use by people of any age.

The legislation could ban a striking array of products simply because they might come into contact with children. For example, shatter-resistant polycarbonate plastic made from bisphenol A is used in baby bottles and food containers, but also to make products ranging from bicycle helmets to eyeglass lenses, as well as components of vital life-saving medical devices such as incubators, dialysis machines and heart-lung machines. Other materials made from bisphenol A are used to formulate medical products such as dental sealants and composites that play an important role in preventing childhood tooth decay. Even the corrosion-resistant resin that lines food and beverage cans, preventing contamination, could be banned if children use these products.

AB319 supporters base their claims on unproven speculation that even extremely low levels of bisphenol A somehow could cause harm to children. Many of the studies are of limited or no relevance, however, and those few studies purporting to show bisphenol A effects at tiny doses have not been sustained when larger and more rigorous studies tried to confirm them -- an essential part of the scientific method to validate results. No matter how many studies are cited, the sum of weak and inconsistent evidence does not make strong evidence.

In stark contrast are recent studies, including one from the U.S. Centers for Disease Control and Prevention, showing that human exposure to bisphenol A is approximately 1 million times lower than the levels shown to be without adverse effect in comprehensive safety studies on laboratory animals. Exposures are well below the safety-protection levels set by government bodies and even below the levels tested in the so-called "low-dose" studies used to support the legislation. It also is noteworthy that researchers in Germany and Japan have found that the human body has a remarkable ability to metabolize and eliminate bisphenol A, which does not accumulate in the body and is eliminated within a day of exposure.

There is no science-based reason for the Legislature to consider AB319. In recent years, government and scientific bodies worldwide have conducted comprehensive examinations of the evidence and nowhere -- not in Europe, Asia or the United States -- have products made from bisphenol A been banned or restricted. Instead, the safety of bisphenol A-based plastics has been reaffirmed repeatedly. Recent examples include comprehensive government assessments in Japan and Europe, a review by an independent panel of scientific experts organized by the Harvard Center for Risk Analysis and a declaration by the U.S. Food and Drug Administration that there is no basis to support banning products made with bisphenol A.

AB319 is bad public policy, crusading against the illusion of harm but actually increasing potential risks to children by restricting safety-enhancing products made with bisphenol A. It is based on insubstantial claims and unproven hypotheses that lack scientific rigor. It ignores sound science and years of research-based evidence. Most important, it preys upon parents' legitimate concern for their children and raises needless fears.