Sunday, November 11, 2007; N02

Have a look at the ingredients list of your favorite shampoo or skin lotion, and chances are you'll see ethylparaben, butylparaben, propylparaben or all of the above. These chemicals are some of the most commonly used preservatives in the cosmetics industry. Parabens are also a source of controversy, primarily because in numerous in-vitro studies they have demonstrated activity similar to estrogen, which may threaten the health of people and aquatic ecosystems.

Although estrogenic compounds can be hormone disruptors -- which can cause male reproductive problems and breast cancer -- the mainstream cosmetics industry and many scientists believe parabens are safe. A 2005 study published in the journal Critical Reviews in Toxicology concluded that daily exposure would present substantially less risk than estrogens consumed in a regular diet. (Food sources of estrogens include pesticides in fruits, vegetables and grains, hormones in commercially raised meat and dairy, and soy, coffee and sunflower seeds.) The Food and Drug Administration's official statement on parabens reads: "FDA believes that at the present time there is no reason for consumers to be concerned about the use of cosmetics containing parabens."

Others aren't so sure. A 1999 report from Environmental Protection Agency scientist Christian Daughton warned that the chemicals in many pharmaceutical and personal-care products, including parabens, could have hormone-disrupting effects on marine life when discharged into water via bathing or excretion: "Although the risk from dermal application in humans is unknown, the probable continual introduction of these benzoates into sewage treatment systems and directly to recreational waters from the skin leads to the question of risk to aquatic organisms."

One well-known study, from 2004, detected parabens in breast tumors. Though the results didn't prove a conclusive link between the two, lead researcher Philippa Darbre of the University of Reading in the United Kingdom notes in an e-mail that more than half of breast cancers occur in the upper outer quadrant of the breast, nearest to where deodorants and cosmetic products are applied. "I have no doubt that all individual cosmetic chemicals will have been tested by all current safety guidelines, but the effects of mixtures are unknown," she says. "Do I avoid all products containing parabens? No. Do I use underarm cosmetics and cosmetic products around the breast area? No, never."

Should you be concerned? More research is needed to determine the extent of parabens' effects on human and ecosystem health. They might not kill you, but it's never a bad idea to use products that are made from organic ingredients. A few lines to check out: Annemarie Borlind, Aubrey Organics, Aura Cacia, Burt's Bees, Dr. Hauschka Skin Care, Pangea Organics and Weleda.

-- Eviana Hartman