April 28, 2004

Via e-mail: marian_Stanley@americanchemistry.com

Marian K. Stanley
Senior Director, Phthalates Esters Panel
CHEMSTAR
American Chemistry Council
1300 Wilson Boulevard
Arlington, VA 22709

RE: Phalates, public health, and “Responsible Care”

Dear Ms. Stanley:

Breast Cancer Action appreciates your letter dated March 2, 2004, taking issue with our letter dated January 26, 2004, which we wrote in response to your initial correspondence dated November 24, 2003. I am afraid that there is little to be gained by further correspondence between the Panel and Breast Cancer Action. But I write in hopes that we can at least make clear where our perspective and values differ from those of the Panel and the American Chemistry Council.

Breast cancer is a hormonally driven disease. While estrogen and progestins have been extensively implicated in the development of breast cancer, the role of androgens and other hormonal factors is less clear. It is precisely this uncertainty that leads us to be concerned about any substances that interfere with the hormonal system, including anti-androgens such as phthalates. Where the effect of a hormonally active substance on breast cancer risk is ambiguous, we believe that “responsible care” requires determining what those effects are before labeling them as “safe.”

In addition, we would expect that a commitment to “responsible care” would lead the panel to identify key sources of phthalate exposure for the most highly exposed individuals in the general population. The US CDC report on human exposures has shown that some individuals have much higher phthalate levels than the rest of the population and the sources of these exposures are not clear. Identifying highly exposed populations is a first step to evaluating potential health effects in humans, and identifying major sources of exposure facilitates exposure reduction in the face of uncertainty about potential health effects.

Breast Cancer Action also believes that a commitment to “responsible care” would mean that the American Chemistry Council would advocate for the EPA to update its phthalate risk assessment to reflect the most current science. As you know, the current reference dose for dibutyl phthalate is based on rat mortality in a 1950s study and does not reflect recent data on endocrine-mediated effects on developing reproductive systems.

Breast Cancer Action is committed to research that will direct us to what is protective as well as what is harmful in relationship to breast cancer risk. But as long as the scientific uncertainty about phthalates remains, we will continue to call for precaution in their use.

Sincerely,

Barbara A. Brenner
Executive Director

Read the ACC response to this letter (in PDF format)…