Despite mounting evidence of severe health risks from two hormone-disrupting chemicals widely used in plastics, the U.S. government has been slow to regulate the substances.

Phthalates, used to soften plastic and make it flexible, are utilized in products ranging from medical devices (including tubing, catheters and intravenous bags) to car interiors and baby products like toys and teethers. Bisphenol A, which makes plastic hard, translucent and shatter-resistant, is used in bottled water and baby bottles, food containers, dental products and the lining of food cans.

Studies have implicated both as endocrine disruptors, or chemicals that mimic the body's natural hormones , and lead to disruptive effects ranging from cancers to birth defects. Because hormones operate at concentrations in the body as low as one part per billion, even small levels of such toxins can have serious effects.

In 2000, a study conducted by the Centers for Disease Control and Prevention discovered that 75 percent of people in the United States contain detectable levels of phthalates in their urine. Another study detected bisphenol A in the bodies of 95 percent of those tested.

The American Medical Association has urged the FDA to require that all medical products containing a certain type of phthalate to be labeled, so that exposure to infants can be limited. The agency has not acted, but more than 100 hospitals have started to remove such products from nurseries.

In 1996, Congress ordered the Environmental Protection Agency ( EPA ) to test pesticides for endocrine disrupting effects, but to date the agency has not tested a single chemical. The Congressional mandate does not even include chemicals found in plastics . Meanwhile, the EPA has asked the National Academy of Sciences to compile a report on phthalates to guide the agency in setting a safe maximum dosage requirement, which does not currently exist. Even after this point, it would still be up to other agencies to impose regulations on the chemicals.

"Europe took [phthalates] out of toys years ago," said Marina Borrone, a California mother. "Why are we so behind?"

The European Union banned three forms of phthalates from children's items in 2005 and restricted three others. Canada has not used phthalates in children's products since 1998, and California introduced a similar ban in October.