Kim Harley, PhD, is a reproductive epidemiologist at the University of California, Berkeley, School of Public Health. She is also associate director for health effects research at the school's Center for Environmental Research and Children’s Health. She spoke with Berkeley Wellness about growing concern over potentially hazardous chemicals in cosmetics and personal care products.
Which chemicals in cosmetics and personal care products are you most worried about?
We’re looking at hormone-disrupting chemicals—ingredients in personal care products that may interfere with the body’s natural hormones. There are four that we are interested in—phthalates, parabens, triclosan, and oxybenzone.
What risks do they pose?
All of these classes of chemicals can disrupt the normal hormones in our bodies. We don’t know everything we’d like to know about what the long term effects are, but there’s reason to be concerned.
Phthalates, which are used in fragrances, nail polish, and other products, have been shown in laboratory studies to block the effects of androgens such as the male sex hormone testosterone. They also mimic estrogen, the female sex hormone. We don’t have a lot of human studies, but there is some evidence that, by disrupting hormones, phthalates may cause neurodevelopment problems, behavioral problems, respiratory conditions such as asthma, and possibly reproductive problems. Pregnant women who are exposed to phthalates, for instance, have an increase risk of delivering baby boys with reproductive system birth defects.
Parabens, which are used as preservatives in cosmetics and personal care products, can mimic estrogen. They have also made breast cancer cells proliferate in laboratory studies. Triclosan is used in antibacterial soaps and some toothpaste, and has altered hormone regulation in animals in some studies. Oxybenzone, used in some sunscreens, also mimics estrogen, and has altered sperm production in some animal studies.
Your most recent research on these chemicals has focused on teenage girls. Why?
We know that women use more personal care products—such as makeup, shampoo, and deodorant—than men do. Teenage girls use even more makeup than adult women. So they have the potential for high exposure to these chemicals. And we’re concerned about teenage girls because they are undergoing rapid reproductive development, so they may be particularly susceptible to hormone disruptors. But I should make it clear that we’re all exposed to these chemicals. And they may pose risks for men as well as women. With hormone disruptors, we worry about critical windows of development, so exposure during pregnancy, early childhood, and adolescence are of particular concern.
Doesn't the government regulate these chemicals in cosmetics and personal care products?
There’s very little regulation of cosmetics and personal care products in the US. The FDA cannot require premarket testing of personal care products. And the ingredients are not always listed on the labels. Phthalates, for instance, are used as a fragrance, and fragrance is considered proprietary. So manufacturers don’t have to list it.
Is it possible to find products that don't contain these potentially dangerous ingredients?
That's one of the questions we wanted to answer. We didn’t take products into the lab to test them, since consumers can’t do that. Instead, we tried to identify products that did not contain these four classes of chemicals based on the labels. We looked to make sure they didn’t list parabens, triclosan, or oxybenzone in their ingredients and we avoided products that listed “fragrance” or “parfum” unless they specifically stated that they were phthalate-free.
In our study, we recruited 100 teenage girls from the Salinas Valley. We tested their urine and found that 90 percent of them showed elevated levels of the four chemicals I mentioned. That’s about the same as we find nationwide in the general population. Then we asked the girls to stop using their regular personal care products and instead choose from among the products we had selected. Three days later, we tested their urine again and found that levels of all four of the chemicals had fallen by 25 to 45 percent. So we were able to identify products that were lower in these chemicals. And we were able to show that, by using them, levels of these chemicals in the body fell.
Beyond reading the labels, are there other ways to find safer personal care products?
I recommend two websites that contain useful information. One is the Environmental Working Group’s Skin Deep database, which allows you to search more than 60,000 products. The EWG has also begun to certify some products as safer. The other is the Campaign for Safe Cosmetics, which contains good general information about how to avoid chemicals in products. Both of these websites have phone apps that you can use to scan barcodes on products while shopping.
Are cosmetics and personal care products the only source of hormone disrupting chemicals?
No. They’re also found in plastics, the lining of some cans, in flame retardant fabrics, and other products. But we think personal care products are the main source of exposure for the four chemicals I mentioned. Cosmetics and other personal care products may pose additional risk because they are applied to the skin, so they can enter that body that way. We also inhale some of these chemicals as fragrances. And we ingest them. One reason women have to reapply lipstick, for example, is because they’ve eaten some of it along with food.
How did the teenage girls in your study react to the findings?
Like most of us, they’d never really thought about what chemicals their personal care products contain. I think they were surprised. Hopefully we raised their awareness and convinced them that with a little bit of care, they can find safer products.
This opinion does not necessarily reflect the views of the UC Berkeley School of Public Health or of the Editorial Board at BerkeleyWellness.com.
Also see What’s in Your Lipstick?