Written by Assemblywoman Fiona Ma, D-San Francisco, AB1108 bans a class of chemicals called phthalates used in cosmetics and to soften and increase the flexibility of plastics.

It's used extensively in toys, teethers and bottles commonly used by children, who put them in their mouths, enabling the chemical to accumulate in the body.

California is the first state to pass a law prohibiting the use of these chemicals, but it's unlikely to be the last. Research has found such chemicals to be toxic. They can accrue in the body, causing reproductive and developmental damage.

Children are particularly susceptible and may be born prematurely if exposed as a fetus to phthalates during pregnancy. They also have been linked to lower testosterone and sperm counts, genital defects and testicular cancer among males.

Phthalates are banned or restricted by the European Union and at least 15 nations. Until now, however, neither the United States nor individual states had restricted use in products manufactured or sold here -- an exception being a 2006 ban passed by San Francisco's Board of Supervisors, when Ma was a member.

Her state legislation mirrors that law, prohibiting manufacturers from selling products with phthalates for use by children younger than 3. Manufacturers and the American Chemistry Council disagree with California's law, warning that a "politics of fear" will force businesses to "take products off the shelves that their customers need and want."

Once again, California is at the forefront of public policy, and lawmakers in at least nine other states hope to follow suit.

Sen. Dianne Feinstein may introduce similar legislation at the federal level. In terms of addressing chemicals that enter our bodies and pose threats to our health, however, AB1108 is but a beginning.

The Centers for Disease Control and Prevention began cataloguing our bodies' chemical burden in the 1990s. The "Body Burden" series published by the Oakland Tribune in 2005, noted that 82,000 chemicals had been identified and 1,000 new ones are added annually. But the effects on our bodies of only 148 had been studied and defined.

We're on the frontier of a research process aimed at determining how the chemicals we consume, touch, inhale, wear and otherwise contact affect our health.

Our nation, medicine, science and business have been slow to study the chemicals that our bodies absorb in everyday life. AB 1108 moves us in that direction.

It, along with increased awareness and wariness about consumer products manufactured and imported from overseas, pose another question.

How do we identify and assess potentially harmful chemicals used in toys and other everyday products that we import?

It's a problem that's received much attention this year. And, as with the recent episode of lead paint being used on children's backpacks, it should be noted that backpacks, rain boots and other common plasticized products often contain phthalates and other potentially harmful chemicals.

Conducting such research is upon us. It's a scientific field destined to grow. AB1108 may be its start.