You can also find them in plastic plumbing pipes, medical tubing and fluid bags, vinyl flooring and other building materials. They are used to soften and increase the flexibility of plastic and vinyl.
In Europe, cosmetics don't contain phthalates, but here in the United States some do.
Phthalates previously were used in pacifiers, soft rattles and teethers. But in 1999, after a push from the U.S. Consumer Product Safety Commission, American companies stopped using them in those products.
"We certainly have the capability, it's a matter of political will," Landrigan said. "We have tried in this country over the last decade to pass chemical safety legislation but the chemical industry and their supporters have successfully beat back the effort."
However, the Food and Drug Administration said two of the most common phthalates, -- dibutylphthalate, or DBP, used as a plasticizer in products such as nail polishes to reduce cracking by making them less brittle, and dimethylphthalate, or DMP used in hairsprays -- are now rarely used in this country.
Diethylphthalate, or DEP, used in fragrances, is the only phthalate still used in cosmetics, the FDA said.
"It's not clear what effect, if any, phthalates have on human health," according to the FDA's website. "An expert panel convened from 1998 to 2000 by the National Toxicology Program (NTP), part of the National Institute for Environmental Safety and Health, concluded that reproductive risks from exposure to phthalates were minimal to negligible in most cases."
But Grandjean is unfazed.
"We know enough about this to say we need to put a special emphasis on protecting developing brains. We are not just talking about single chemicals anymore. We are talking about chemicals in general."
"This does not necessarily mean restrict the use of all chemicals, but it means that they need to be tested whether they are toxic to brain cells or not," he said.
"We have the test methods and protocols to determine if chemicals are toxic to brain cells. If we look at this globally, we are looking at more than a generation of children -- a very high proportion of today's children have been exposed to lead, mercury and other substances, including substances that have not yet been tested but are suspect of being toxic to brain development."
The Environmental Working Group is an environmental health research organization that specializes in toxic chemical analysis and has long called for reforms. In 2004, the group tested 10 samples of umbilical cord blood for hundreds of industrial pollutants and found an average of 200 in each sample.
"Here in the U.S., the federal law put in place to ostensibly protect adults and children from exposures to dangerous chemicals, including those that can present serious risks to the brain and nervous systems, has been an abject failure," said Environmental Working Group spokesman Alex Formuzis.
"The 1976 Toxic Substances Control Act has instead been largely responsible for the pollution in people beginning in the womb, where hundreds of industrial contaminants literally bathe the developing fetus."
Landrigan is recruiting pregnant women for a new study that will test for chemical exposures. He said it's inevitable that over the next few years more chemicals will be added to the list.
His concern? "The ability to detect these chemicals lags behind the chemical industries' ability to develop new chemicals and put them into consumer products. That's why we need new legislation in this country to close that gap."
"We are lagging behind," Grandjean said. "And we are putting the next generation of brains in danger."