Harmful Chemicals Found in Hair Extensions: New Study Raises Health Concerns for Black Women

Hidden Hazards in Hair Extensions: Study Reveals Widespread Chemical Concerns

A new study has uncovered a concerning array of potentially harmful chemicals in widely available hair extensions, including those made from human hair. The research, conducted by the Silent Spring Institute, represents the most detailed chemical review to date of this largely unregulated beauty product category, raising urgent questions about consumer safety, particularly for Black women who use these products at disproportionately higher rates.

Published in the American Chemical Society journal Environment & Health, the findings come amid growing awareness of the potential long-term health effects associated with hair extensions. More than 70 percent of Black women report using hair extensions at least once a year, compared to less than 10 percent of women from other racial and ethnic groups. These products are often chosen for cultural expression, personal style, and convenience.

“While prior reports have found some chemicals of concern in hair extensions, there’s still much we don’t know about their overall chemical makeup,” says Dr. Elissia Franklin, a research scientist at Silent Spring Institute and lead author of the study. “We wanted to get a better picture of the extent of the problem. This is an industry that has long overlooked the health of Black women, who should not have to choose between cultural expression, convenience, and their health.”

Chemical Treatments and Limited Transparency

Hair extensions are manufactured from either synthetic fibers or bio-based materials, which can include human hair, banana fiber, or silk. To achieve desired qualities like flame resistance, waterproofing, or antimicrobial properties, manufacturers frequently treat these fibers with various chemicals. However, companies are not typically required to disclose the specific chemicals used, leaving consumers unaware of potential health risks associated with prolonged exposure.

Because hair extensions are worn directly against the scalp and neck, skin contact is often extended. When extensions are heated during styling, chemicals can be released into the air, potentially leading to inhalation exposure.

How the Study Was Conducted

Researchers purchased 43 hair extension products from both online retailers and local beauty supply stores. These products were categorized by fiber type – synthetic (primarily plastic polymers) or bio-based (human, banana, or silk). The team also documented the claims made on product packaging, such as “flame retardant,” “water resistant,” or “green” claims like “no PVC” or “non-toxic.”

Employing a technique called non-targeted analysis, the researchers searched for a broad spectrum of chemicals, including those not routinely screened for in consumer goods. Using two-dimensional gas chromatography with high-resolution mass spectrometry, they identified over 900 chemical signatures, representing both known and previously unidentified compounds. Machine-learning tools were then used to compare these signatures against an extensive chemical database, allowing the team to identify 169 distinct chemicals spanning nine major structural classes.

Concerning Findings: Cancer Links and Hormone Disruption

The testing revealed numerous substances linked to adverse health effects, including cancer, hormone disruption, developmental harm, and immune system impacts. These included flame retardants, phthalates, pesticides, styrene, tetrachloroethane, and organotins.

Key findings from the study include:

• All but two of the 43 samples tested contained hazardous chemicals. The two exceptions were products specifically labeled as “non-toxic” or “toxic-free.”
• A total of 48 identified chemicals appear on major hazard lists, with 12 listed under California’s Proposition 65 as known to cause cancer, birth defects, or reproductive harm.
• Four different flame retardants were detected in both synthetic and bio-based products.
• Seventeen chemicals linked to breast cancer were found in 36 samples, including compounds known to disrupt hormones, potentially increasing cancer risk.
• Nearly 10 percent of products contained toxic organotins, in some cases at levels exceeding health-based limits established in the European Union.

“We were especially surprised to find organotins,” Dr. Franklin noted. “These are commonly used as heat stabilizers in PVC and have been linked with skin irritation, which is a common complaint among hair extension users.” Organotins have also been associated with cancer and hormone disruption.

Calls for Increased Regulation and Consumer Protection

With the global hair extension market projected to exceed $14 billion by 2028, and the United States being a leading importer, Dr. Franklin argues that increased oversight is crucial. “These findings make clear that stronger oversight is urgently needed to protect consumers and push companies to invest in making safer products,” she says.

The presence of many of the detected substances on California’s Proposition 65 list suggests that hair extensions may require clearer warning labels and more rigorous regulatory scrutiny.

Legislative efforts to address these concerns are underway. In New York, lawmakers have proposed legislation mandating ingredient disclosure by manufacturers of synthetic braids and hair extensions. A similar bill in New Jersey seeks to prohibit the use of certain harmful chemicals in these products. At the federal level, the Safer Beauty Bill Package, introduced in Congress last year, includes provisions to direct the Food and Drug Administration to regulate the safety of synthetic braids and hair extensions.

This research was supported by a Beauty Justice Grant from the Environmental Defense Fund and charitable donations to the Silent Spring Institute, including funding for the Institute’s Safer Chemicals Program.