Endocrine-Disrupting Agents Found in Black Women's Hair Products

Marlene Busko

May 04, 2018

Hair care products commonly used by black women and children in the United States to relax or straighten hair contain chemicals associated with endocrine disruption and asthma, researchers report.

Specifically, 18 tested hair care products each contained 6 to 30 endocrine-disrupting or asthma-associated chemicals.

This early research step may help explain why black women have higher levels of certain hormone-disturbing chemicals in their bodies, as well as hormone-related biological differences such as earlier puberty, and higher rates of asthma, say Jessica S. Helm, PhD, from the Silent Spring Institute in Newton, Massachusetts, and colleagues. Their study was published online April 23 in Environment Research.

"In general, many of the chemicals that we detected weren't labeled," Helm told Medscape Medical News.

"These results indicate the need for more information about the contribution of consumer products to [chemical] exposure [racial] disparities," according to Helm and her coauthors.

"A precautionary approach would reduce the use of endocrine disrupting chemicals in personal care products and improve labeling so women can select products consistent with their values," they conclude.

Data in Line With CDC Figures, Detox Me App Could Help

The research is in line with data from the US Centers for Disease Control and Prevention (CDC), which shows that black women have higher levels of some phthalates (used as a solvent in fragrances) and parabens (used as a preservative) in their bodies than white women.

"Products that we tested frequently contained higher levels of the parabens and diethyl phthalates, suggesting that [hair care products] are potentially a source of some of those [higher levels in the bodies of] black women," Helm noted.

"Diethyl phthalate is frequently a fragrance ingredient, so by looking for products that don't have paraben or fragrance on the label, [consumers] can reduce...exposure to those chemicals." People can also look for ingredients from natural sources, she advised.

"And we have our [free] Detox Me app, which contains these and other tips" to lower exposure to potential toxins in personal care and other products, she noted.

Straighteners and Frizz Tamers

Black women have earlier puberty, higher rates of hormone-related uterine fibroids and infertility, and more aggressive forms of breast and uterine cancer, with rates of these cancers increasing, Helm and colleagues note.  

And different hair care products used by black women and children are a potential source of these disparities in hormone-related health.

The researchers aimed to determine, for the first time, the concentrations of 66 endocrine-disrupting chemicals (parabens, phthalates, bisphenol A, antimicrobials, alkylphenols, fragrance, cyclosiloxanes, and UV filters) and asthma-associated chemicals (phthalates, bisphenol A, antimicrobials, ethanolamines, fragrances, and glycol ethers) in six types of hair care products commonly used by black women and children.

Based on a survey of black women living in New York City in 2004–2005, they identified 18 commonly used hair care products: six hair lotions, four root stimulators, three hair relaxers (including two for children), three anti-frizz agents, one hot-oil treatment, and one leave-in conditioner.

Using gas chromatography/mass spectroscopy researchers detected 45 of these 66 chemicals in the 18 products purchased in 2008. Details are provided in the online supplement to their article.

All products contained fragrance. Most (78%) contained parabens and 72% contained a UV filter (used as a sunscreen and to prevent product degradation).

Anti-frizz products contained cyclosiloxanes, used to increase spreadability, levels of which were the highest of all chemicals.

Root stimulators, hair lotions, and relaxers frequently contained nonylphenols, parabens, diethyl phthalate, and fragrances.  

And 11 products contained endocrine-disrupting chemicals prohibited in the EU Cosmetics Directive (bisphenol A, benzyl butyl phthalate, bis[2-ethylhexyl] phthalate, 4-t-nonylphenol, diethanolamine) or regulated under California's Proposition 65 because of their links to reproductive toxicity and cancer.

The hair relaxers for children had the highest levels of five chemicals prohibited in the European Union or regulated in California.

Incomplete Labeling Is Worrisome

Importantly, most chemicals (84%) were not specifically identified on the product label and may have been listed as "fragrance," for example. However, chemicals detected at higher concentrations (more than 0.1% by weight) were more often listed on the label.

"Incomplete labeling is worrisome," the researchers write, "because product ingredient labels are often the only source of information for individuals seeking to reduce their exposure to a chemical of concern."

It is also important to note, Helm said, that women may use multiple products over a long time and effects could be cumulative.  

"This study is evidence that hair products are an important source of toxic chemicals and that we need to remove these risks to protect black women's lives and prevent harm," Janette Robinson Flint, executive director of Black Women for Wellness, a nonprofit based in California that conducts research and education on toxic chemicals in personal care products through its Healthy Hair Initiative, said in a statement.

The study was partially funded by the Rose Foundation, Goldman Fund, and Hurricane Voices Breast Cancer Foundation.

Environ Res. Published online April 25, 2018. Full text

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