Toxic Chemicals in Hair Extensions Raise Health Concerns, Especially for Black Women

A modern investigation by the Silent Spring Institute has revealed the presence of dozens of potentially harmful chemicals in widely sold hair extensions, including those made from human hair. The findings, representing the most detailed chemical review to date of this largely unregulated beauty product category, add strong evidence that hair extensions may pose health risks, particularly for Black women, who leverage these products at disproportionately higher rates.

Growing Concerns and Disparities in Usage

The study, published in the American Chemical Society journal Environment & Health, comes amid increasing concern about the long-term health effects of hair extensions. More than 70 percent of Black women report wearing hair extensions at least once a year, compared to less than 10 percent of women from other racial and ethnic groups. Extensions are frequently used 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. We wanted to get a better picture of the extent of the problem,” says Dr. Elissia Franklin, a research scientist at Silent Spring Institute. “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 Lack of Transparency

Hair extensions are manufactured from synthetic fibers or bio-based materials, including human hair. Manufacturers often treat these fibers with chemicals to make them flame resistant, waterproof, or antimicrobial. However, companies rarely disclose the specific chemicals used, leaving consumers unaware of potential health risks from prolonged wear. Because the fibers have direct and extended skin contact, and can release chemicals into the air when heated during styling, wearers may be exposed through skin absorption and inhalation.

How the Study Was Conducted

Researchers purchased 43 popular hair extension brands from online retailers and local beauty supply stores. The products were categorized by fiber type – synthetic (primarily plastic polymers) or bio-based (including human, banana, or silk) – and packaging claims were documented. A non-targeted analysis was then applied to search for a broad range of chemicals, identifying over 900 chemical signatures and 169 identified chemicals spanning nine major structural classes.

Harmful Chemicals Detected

The testing uncovered numerous substances linked to cancer, hormone disruption, developmental harm, and immune system effects. These included flame retardants, phthalates, pesticides, styrene, tetrachloroethane, and organotins. Key findings include:

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

“We were especially surprised to find organotins,” says Franklin. “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 similarly been linked with cancer and hormone disruption. Silent Spring Institute

Calls for Increased Regulation

The global hair extension market is projected to surpass $14 billion by 2028, with the United States as a leading importer. Given the size of the market and the chemicals detected, Franklin argues that increased oversight is necessary. “These findings make clear that stronger oversight is urgently needed to protect consumers and push companies to invest in making safer products,” she says.

Many of the detected substances are included under Proposition 65, suggesting that hair extensions may warrant clearer warnings and closer regulatory scrutiny. Legislative efforts are underway to address these concerns. In New York, legislation has been introduced to require manufacturers of synthetic braids and hair extensions to disclose all ingredients. A similar bill in New Jersey would prohibit certain harmful chemicals in synthetic hair products. At the national level, the Safer Beauty Bill Package contains provisions to direct the Food and Drug Administration to regulate the safety of synthetic braids and hair extensions. SpecialChem

This research was funded by a Beauty Justice Grant from the Environmental Defense Fund and charitable donations to Silent Spring Institute. Hoodline