The Environmental Working Group (EWG) say that consumers are exposed to phthalates from a wide range of sources, including cosmetics products, food packaging and children's toys, and that an investigation into the effects of such cumulative exposure is necessary.
The request was made at the first meeting of the National Research Council's project investigating the health risks of phthalates, held yesterday in Washington.
According to the EWG it has long been known that "health risks are additive across chemicals with similar target organs and mechanisms of action".
Furthermore, the group reference scientific studies that illustrate the additive risks of phthalates in particular, claiming that individuals exposed to two or more phthalates could experience effects much greater than would be expected by a simple addition of the doses.
"We believe that a cumulative human health risk assessment is needed to protect public health" concludes the EWG vice president for research Jane Houlihan.
In addition, the group claim that a significant body of scientific data is now available suggesting that phthalates affect the reproductive system of humans as well as those of animals in lab tests.
The chemicals have been under scrutiny for some time now, however the picture remains unclear as the term phthalates refers to a large family of compounds with very different chemical profiles, relatively few of which are used in personal care products.
In September, the Natural Resources Defense Council (NRDC) warned consumers to avoid exposure to the phthalate DEP, which helps fragrances linger after application.
While the consumer group claimed DEP posed a serious health risk, the Fragrance Materials Association (FMA) and the European Commission's Scientific Committee on Consumer Products (SCCP) both insist that DEP is safe for use in cosmetics at current levels.
The FMA said the chemical profiles of different phthalate compounds differ significantly, which explains why DEP is considered safe in Europe while the phthalates DBP and DEHP are banned in the continent.
The National Research Council's project, launched earlier this year, is funded by the EPA and will investigate the health risks posed by phthalates and the potential for conducting cumulative risk assessment.
Representatives from the American Chemistry Council, the National Center for Environmental Assessment and the National Toxicology Program were also among those speaking at the meeting.