A new study by a Newton-based research group finds that hair products used frequently by black women contain dozens of harmful chemicals that may disrupt hormones.

Silent Spring Institute, which focuses on environmental chemicals and women’s health, tested products like hair straighteners and moisturizers. In many, it found chemicals linked to health problems, including birth defects and cancer.

I spoke with the study’s lead author, Jessica Helm. I also reached out to three major hair-product manufacturers for a reaction but got no response. This interview has been edited and condensed.

Can you summarize the findings of the study?

Helm: This is the first study that's measured endocrine-disrupting chemicals and hair products that are used by black women. When we went to detect these chemicals, we found dozens of endocrine-disrupting chemicals in these hair products, including multiple chemicals that have been banned in the European Union and also regulated by California's Proposition 65.

We also found that hair products for children contained the highest levels of multiple banned and regulated chemicals. Another interesting point is that the vast majority of the detected chemicals were actually not listed on the product label.

Do you know why these harmful chemicals are not listed on the label and why it's not required for companies to put them there?

The FDA requires a listing of intentionally added ingredients. You would have to ask the companies themselves why these detections aren't labeled. But some of them may be present due to impurities, or were added during manufacturing, or possibly came from the packaging ingredients.

What brands or types of products were reviewed in this study?

We targeted a couple of different kinds of products, including hair relaxers, which are used to straighten hair, as well as hair lotions, which are basically moisturizers to soften and moisturize hair. We also looked at anti-frizz products, leave-in conditioner and hot oil for hair. Many of these products are intended to moisturize or to straighten hair.

What is your message to consumers after this study? What ingredients should they look out for and potentially avoid?

One suggestion is to look for paraben-free and fragrance-free products. But most of the chemicals that we found weren't listed on the product label, including some parabens and fragrances. We did find that parabens and the word "fragrance" were labeled more often than other chemicals. So, looking for those on the label should help.

We do know that fragrance-free products can be hard to find, especially in hair products. We also hope that these findings will encourage manufacturers to offer more in the area of fragrance-free products.

From our earlier research, we also know that products that are made from plants or made with organic ingredients tend to have lower levels of endocrine-disrupting chemicals. We also have a mobile app called Detox Me that is intended to help individuals reduce exposures. We've actually modified our content based on some focus groups that we did in our research to make it more relevant to black women and to black hair products.

What are some of the differences between hair products targeted toward black women and hair products targeted toward white women?

Black women, in addition to hair products that are used by women in general, also commonly use products that are intended for moisturizing and also sometimes for straightening. These products tend to have those properties.

What are the biological factors that put black women more at risk for these hormone-mediated health problems?

We know that black women have higher rates of certain hormone-related health problems. Black girls go through puberty at younger ages than other girls. Black women have higher rates of fibroids and more severe fibroids. They have higher rates of infertility, and also rising rates of endometrial and breast cancers.



What are the next steps?

We hope that companies will use this research to pay more attention to where the ingredients in their products are coming from, what ingredients might be in there and to really try to formulate products to reduce exposures for women in general and for black women in particular.

Mariel Cariker is a WBUR intern.