California Governor Arnold Schwarzenegger has signed a state law that will require manufacturers to remove six types of phthalates from products intended for children under the age of three. The San Francisco Chronicle quotes the bill’s author, Assemblywoman Fiona Ma:

“California continues to lead the nation in protecting children from dangerous chemicals and in safeguarding our environment,” she said. “AB1108 sends a clear message to the Consumer Product Safety Commission that if the Bush administration won’t act, states will.”

Environmental and breast cancer groups who backed the measure say that they’ll help nine other states (Texas, Illinois, Florida, Massachusetts, Maryland, Washington, Maine, Connecticut, and New York) pass similar laws. The EU has already banned phthalates in toys; it instituted a temporary ban in 1999, and the permanent one took effect in 2006.

Phthalates are widely used as plasticizers, and they’re widely detected in human blood and urine samples. The Environmental Working Group offers a succinct summary of why this is worrisome:

In laboratory animals, fetal exposure to phthalates causes significant developmental toxicity, especially of the male reproductive system (CERHR 2000). In adult animals, phthalates damage the reproductive organs, adrenal, liver, and kidney (CERHR 2000).

In utero exposure to high levels of phthalate metabolites are associated with marked differences in the reproductive systems of baby boys (Swan 2005); the exposure levels associated with these health effects were not extreme, but rather were typical for about one-quarter of all U.S. women (Marsee 2006).

Adult men with high levels of phthalates have lower sperm motility and concentration and alterations in hormone levels (Duty 2003, 2004, 2005). Concentrations of two phthalates in house dust are associated with asthma and rhinitis in a study of 400 children, half of whom had allergies (Bornehag 2004).

Environmental Health News has links to lots of recent studies on phthalates, too.

In 2005, after the EU passed its phthalate ban, Alexander H. Tullo examined the alternatives in a Chemical & Engineering News article. He reported that plenty of plasticizer alternatives exist, but they cost more – and one researcher predicted that they wouldn’t be broadly tested until phthalate bans are imposed. Whether California’s legislation will spread to other states remains to be seen, but it’s likely to have an effect on the products we see on store shelves nationwide.