A recent study is giving naturals retailers another talking point in their quest to educate consumers—and fill their personal care aisles. At the annual American Society of Cell Biology meeting held Dec. 5 in Washington, D.C., Elias Aizenman, professor of neurobiology at the University of Pittsburgh School of Medicine, presented a paper on a preservative found in conventional cosmetics and body care products. The preservative, methylisothiazolinone, is a biocide used to prevent bacteria from developing.
According to Aizenman, lead researcher on the study, the chemical caused neurons to die in experiments with rats' brain cells. The study found that not only did direct exposure to the chemical cause neuronal death, but, researchers wrote, "In addition, our results suggest that prolonged exposure to low levels of MIT and related compounds may have potentially damaging consequences to the developing nervous system."
However, the Cosmetic, Toiletry, and Fragrance Association put out a release stating, "Cosmetic exposure is so much lower than what is presented in this abstract as to make the study meaningless for safety evaluation purposes regarding cosmetic products."
According to Tim Kropp, Ph.D., senior scientist for the Washington, D.C.-based Environmental Working Group, the study's results aren't necessarily revolutionary. "It may surprise people to know that consumer products are not safety-tested before they are put on store shelves, and this includes the personal care products we all put on our skin and hair each day. We just don't know the long-term effects of most of these ingredients, either alone or in combination. But in the case of methylisothiazolinone, we see that the cosmetic industry's review board knew there were risks associated with it, but declared it safe for use."
Tim Schaeffer, brand manager for Petaluma, Calif.-based Avalon Natural Products, said "Methylisothiazolinone is a relatively common preservative and was generally considered safe. However, a lot of things have been considered safe for use, [only] to discover the opposite, so that doesn't mean much these days, as science improves our understanding of our interactions with these chemicals on a daily basis." He said the next step would be to learn what concentration levels are of concern and over what period of time. "Given the task preservatives must perform it's not surprising that health science is determining them to be harmful; that's what they're designed to do—to kill cells."
A list of products containing MIT can be found at National Institutes of Health. And don't worry, you won't find any naturals brands there.