A new scientific study has found that many widely used hair extension products contain chemicals linked to cancer and hormone disruption, raising concerns about consumer safety and regulation within the beauty industry. A study published by the Silent Spring Institute on Feb. 19 in the American Chemical Society Journal Environment & Health examined 43 popular hair extension products that can be purchased online and from retailers. The findings show there were hazardous chemicals in nearly all of the samples.

According to the study, hair extensions, including both synthetic fibers and products made with real human hair, often undergo extensive chemical treatments to improve durability and heat resistance. Often, manufacturers are typically not required to disclose the substances used during production, making consumers unaware of the dangers and possible long-term health risks.

Among the most concerning discoveries were the flame retardants, pesticides, styrene, tetrachloroethane and organotins. These chemicals are commonly used in plastic manufacturing. Organotins were found in nearly 10% of products tested and has been linked with skin irritation and hormone disruption. In some cases, the amount of organotins exceeded the limits the European Union has deemed hazardous.

Because hair extensions sit directly against the scalp and neck for extended periods, there is prolonged skin exposure. Meanwhile, heat styling, such as blow-drying, curling or straightening of the hair can release inhalable chemicals.

Lead author Elissia Franklin stated that the findings highlight a major gap in consumer protection within the beauty industry. She also emphasized that “[Consumers] should not have to choose between cultural expression, convenience, and their health.” 

The study raised broader questions about how everyday beauty products are regulated and who is accountable when safety standards aren’t fully enforced.

New York lawmakers have introduced legislation that would require manufacturers of synthetic braids and hair extensions to disclose ingredient information;.Meanwhile, New Jersey lawmakers aim to ban certain harmful chemicals used in synthetic hair products altogether.

Researchers hope the study will encourage stronger regulations, increased transparency from manufacturers and innovations toward safer cosmetic alternatives.