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Date: Dec. 18, 2008
Contacts: Jennifer Walsh, Media Relations Officer
Alison Burnette, Media Relations Assistant
Office of News and Public Information
202-334-2138; e-mail <news@nas.edu>

FOR IMMEDIATE RELEASE

EPA Should Pursue Cumulative Risk Assessment of Phthalates and Other Chemicals

WASHINGTON -- The U.S. Environmental Protection Agency should examine whether combined exposures to chemicals known as phthalates could cause adverse health effects in humans, says a new report from the National Research Council. In addition, this analysis, called a cumulative risk assessment, should consider other chemicals that could potentially cause the same health effects as phthalates, instead of focusing on chemicals that are similar in structure, which is EPA's current practice. Furthermore, EPA should consider using the recommended approach for future cumulative risk assessments on other kinds of chemicals.

Phthalates are used in a wide variety of consumer products, such as cosmetics, medical devices, children's toys, and building materials. In light of concerns, the European Union and the United States have passed legislation that restricts the concentrations of several phthalates in children's toys, and the European Union has also banned several phthalates from cosmetics. EPA asked the Research Council to recommend whether it should conduct a cumulative risk assessment for phthalates, and if so, how it should be framed. Accordingly, the National Research Council report is not a comprehensive profile on the health effects of phthalates.

Recent animal studies have increased understanding of the potential risks from phthalates, although few human studies on the health effects of phthalates are available, said the committee that wrote the report. To decide whether a cumulative risk assessment is warranted, two factors needed to be determined: whether humans are exposed to multiple phthalates at any given time, and whether sufficient evidence exists linking exposures to similar adverse health effects. The committee established that recent studies have shown widespread human exposure to multiple phthalates, including in utero exposure.

Then, the committee reviewed animal research and found that exposure to various phthalates in lab animals produced similar health outcomes, including a range of effects on the development of the male reproductive system. The most notable effects in male rats are infertility, undescended testes, malformation of the penis, and other reproductive tract malformations. However, the severity of effects differs among phthalates; some exhibit less severe or no effects. Furthermore, the age of the animals at the time of exposure is critical to the severity of the effects. For example, the fetus is most sensitive. Given that multiple human exposures to phthalates occur and that research shows exposure to different phthalates leads to similar outcomes in lab animals, a cumulative risk assessment is called for, the committee said.

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