The American Council on Science and Health, supported by grants from corporations and foundations, contends that claims of harm from phthalates are exaggerated and that the chemicals are safe. In its report last year, the National Academy panel said phthalates can cause health problems in humans and wildlife, including birth defects and reproductive disorders. The panel called for research on how such contaminants could be harming human health. To begin answering that question, scientists must determine the levels and types of phthalates in people. The main way the chemicals enter the body is through food, experts say, though they also can be absorbed through the skin and inhaled.
Some chemicals can pass from mother to fetus in the womb.
Scientists and health experts familiar with phthalate research say they are eager to compare the levels of the chemicals the CDC detected in people with levels that have caused birth defects and reproductive disorders in laboratory experiments with rats. Earl Gray, an EPA research chemist and phthalate expert who has done some of the rat experiments, said one of his concerns is that tests that look at a chemical's potential effects on offspring are not required when chemicals are produced and used in industry. Some products are labeled as containing phthalates, but some are not, and manufacturers are not required to release that information, Gray said. Scientists have known for several years that phthalates were present in human blood serum and urine. But most scientists until now assumed the phthalates were contaminants that found their way into samples from plastic laboratory equipment after the samples were drawn from people, Guillette said.