A survey finding widespread detection of hazardous chemicals in headphones from major brands sold in Europe has fuelled controversy.

Gizmodo Japan reported on March 19 that an investigation conducted by Czech environmental group Arnika as part of the ToxFree LIFE for All project confirmed endocrine-disrupting substances in all 81 headphone and earphone products sold in five Central European countries and on online marketplaces. Major global brands were included in the sample.

The survey assessed products under 3 criteria: skin-contact areas, non-contact areas and the overall product. It found 44 percent of all products received a red, or dangerous, rating, while 42 percent were graded green, or low risk, and 14 percent were classified yellow, or caution. In internal components that do not directly touch skin, the share rated yellow or red reached 58 percent, indicating a higher potential for exposure in areas consumers are less likely to notice.

Safety differences were also found by product. Some models from global brands A and B received green ratings across all categories, but other models within the same brands were rated red, producing mixed results. Some products from brand C and models for children were classified as risky in non-contact areas and in overall assessments.

Some of brand D's gaming headsets and certain products from brand E were rated red across all 3 criteria, placing them in a relatively higher-risk group.

The substance identified as the core issue was bisphenol A. It was detected in 98 percent of surveyed items, and bisphenol S, a substitute used to avoid regulation, was found in more than 75 percent. Concentrations in some products were found to significantly exceed levels proposed by the European Chemicals Agency. Bisphenols disrupt hormonal action in the body and may affect reproductive function and development over the long term, prompting the European Union to tighten regulation.

Experts stressed that these chemicals do not simply remain inside products. They said heat and sweat during activities such as exercise could increase the likelihood of absorption into the body through the skin. They added that the detected levels do not require immediate concern about health damage, but long-term repeated exposure could be a potential risk factor.

After the results were released, some European retailers stopped selling the products or began reviewing them. Some manufacturers countered that their products meet legal safety standards and raised questions about the transparency of the survey data.

Experts said the findings show that chemical exposure can occur even from everyday electronic devices, beyond the risk of specific products. They pointed to a need for manufacturers to disclose ingredients and strengthen controls, and for regulators to set stricter standards.

The full report can be viewed on Arnika's website at arnika.org.