An investigation by the ToxFree LIFE for All project has found that every single pair of headphones tested contained hazardous chemicals linked to cancer, hormone disruption, and fertility problems, raising concerns about long-term exposure from devices millions of people wear daily.
Researchers analyzed 81 headphone models, including both in-ear and over-ear designs, purchased across European markets and major online platforms. The results showed widespread contamination across brands, including major manufacturers such as Bose, Panasonic, Samsung, and Sennheiser.
The most commonly detected substance was bisphenol A (BPA), found in 98% of samples. BPA is a well-known endocrine disruptor that mimics estrogen and has been associated with cancer, infertility, and early puberty. Its replacement, bisphenol S (BPS), appeared in more than three-quarters of the headphones tested. Both chemicals can migrate from plastic materials and be absorbed through the skin, especially when heat and sweat are present during exercise or extended use.
Scientists also detected phthalates, which are linked to reproductive toxicity and reduced fertility, along with chlorinated paraffins that can damage the liver and kidneys. Flame retardants, including brominated and organophosphate compounds, were also found. These substances are known to interfere with hormone systems and may contribute to long-term health risks.
Researchers warned that daily exposure could allow these chemicals to gradually enter the body through skin contact. While individual exposure levels from headphones alone are relatively low, experts are concerned about the cumulative effect from multiple sources. This “cocktail effect,” where people are exposed to many small doses of harmful chemicals across different products, may significantly increase long-term health risks.
Campaigners described the findings as a market-wide failure in chemical safety transparency. They are calling for stricter regulations, bans on entire classes of endocrine-disrupting chemicals, and clearer disclosure from manufacturers about the substances used in consumer electronics.
Headphones have evolved from occasional accessories into devices worn for hours each day, making prolonged skin contact unavoidable. Researchers say this constant exposure makes even low levels of chemical migration a serious concern, particularly for teenagers and frequent users.