Hazardous substances found in all headphones tested by ToxFREE project

2026-03-1423:0010275arnika.org

PRAGUE, 18 February 2026 – A landmark international study across five Central European countries has found hazardous chemicals in every single pair of headphones analysed, from premium models to cheap…

PRAGUE, 18 February 2026 – A landmark international study across five Central European countries has found hazardous chemicals in every single pair of headphones analysed, from premium models to cheap imports. Authors say the results reveal a systemic failure in consumer safety regulation across the electronics industry. The investigation, conducted as part of the EU-funded ToxFree LIFE for All project, analysed 180 samples of hard and soft plastic components from 81 headphone products marketed to children, teenagers, and adults in the Czech Republic, Slovakia, Hungary, Slovenia, and Austria.

Researchers discovered that nearly all headphones contain bisphenols, chemicals known to interfere with hormones. The widely restricted Bisphenol A (BPA) appeared in 98% of samples, while its substitute, Bisphenol S (BPS), was found in over three-quarters. Maximum concentrations reached 351 mg/kg, dramatically exceeding the 10 mg/kg limit originally proposed by the European Chemicals Agency (ECHA).

"These chemicals are not just additives; they may be migrating from the headphones into our body," said Karolina Brabcová, chemical expert at Arnika. "Daily use—especially during exercise when heat and sweat are present—accelerates this migration directly to the skin. Although there is no immediate health risk, long-term exposures, especially vulnerable groups like teenagers, are of great concern. There is no 'safe' level for endocrine disruptors that mimic our natural hormones."

Regrettable Substitutions

The study confirms a broader trend of so‑called regrettable substitution, where banned chemicals are replaced by slightly modified cousins that behave in almost the same way. Manufacturers often change just part of the molecule, so the substance falls outside current rules, but its core structure — and therefore its toxic effects — remain very similar. In flame retardants, this means older halogenated substances are increasingly swapped for organophosphate flame retardants such as RDP (Resorcinol bis(diphenyl phosphate)), an alternative to TPhP that recent research links to neurotoxicity and endocrine‑disrupting effects on thyroid and oestrogen systems.

The highest level of harmful plasticisers and chlorinated paraffins was detected in a sample bought from an international online marketplace. At the same time, the study shows that even established
brands are not immune: hazardous chemicals appeared across the entire price range, so a higher price still does not guarantee a safer product.

A Call for Urgent EU Reform

The "ToxFree LIFE for All" partnership is calling on European policymakers to move away from the slow "substance-by-substance" approach and adopt group-based restrictions on flame retardants and bisphenols. “This commitment from the Chemicals Strategy for Sustainability adopted in 2021 is to be fulfilled as soon as possible given the recent findings from the sampling campaign”, concluded Brabcová.

“The evidence is clear: our current laws are slow and outdated to protect vulnerable consumers, who are exposed to harmful chemicals. However, they lack specialised knowledge, skills, and resources to protect themselves,” says Emese Gulyás, a sustainable consumption expert at the Hungarian Association of Conscious Consumers and head of the ToxFree Life for All partnership. “We need immediate, harmonised EU regulations that ban entire classes of toxic chemicals. This is the only way to protect consumers while fostering a safe circular economy where recycled materials aren’t poisoned by ‘legacy toxins.”

Key Findings:

  • 81 headphone models tested across Czechia, Slovakia, Hungary, Slovenia, and Austria
  • 100% contained traces of hazardous chemicals (bisphenols, phthalates, flame retardants)
  • Up to 351 mg/kg of bisphenols detected—35× higher than proposed EU limits
  • Product from online marketplaces (e.g. Temu) showed the highest toxicity

How Consumers Can Act

While individual choice is limited by market-wide contamination, the project recommends that consumers:

Join over 11,000 citizens demanding safer products at ToxFreeProductsNow.eu.

About ToxFree LIFE for All: The ToxFree LIFE for All project (LIFE22-GIE-HU-101114078) is an EU-funded initiative aimed at protecting citizens from hazardous chemical exposure through awareness, testing, and policy advocacy. Partners include VKI (Austria), Arnika (Czechia), dTest (Czechia), TVE (Hungary), and ZPS (Slovenia).


Funded by the EU Life Programme (LIFE22-GIE-HU-ToxFree LIFE for All, 101114078) and the Ministry of Environment of the Czech Republic. Views and opinions expressed are, however, those of the author(s) only and do not necessarily reflect those of the European Union or other donors. Neither the European Union nor the granting authority can be held responsible for them.

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Comments

  • By maxbond 2026-03-150:542 reply

    I wear cheap bone conduction headphones constantly. So I think I'm getting a lot of exposure. I think I'm going to find some kind of bandage or tape which doesn't have this problem, and put it on the headphones. And I'll try to wear them less often, and try especially to avoid sweating in them.

    Does anyone have any other ideas to mitigate exposure?

    • By terribleperson 2026-03-151:211 reply

      My immediate idea was to cover contact surfaces. My first thought of what to cover them with was more plastic...

      I guess the proper thing to do would be to use big over-the-ear headphones and cover the cushions with fabric.

      • By freehorse 2026-03-153:07

        > My first thought of what to cover them with was more plastic

        Tinfoil is a good alternative, with the added benefit that it can also protect from other things /s

    • By booleandilemma 2026-03-152:402 reply

      Is bone conduction itself safe for long-term usage? I feel like we're taking advantage of a quirk and using the body in a way it's not meant to be used, kind of like smoking or vaping.

      • By ffsm8 2026-03-157:23

        Huh, why? You're just sending the sound waves through the bone instead of the air into the ear canal

        It's also not a new technology you know, it has been used for decades in hearing aids

      • By maxbond 2026-03-153:03

        It definitely isn't comparable to smoking or vaping. Those introduces a lot of material to your body that's well established as harmful. To name just a few, formaldehyde, carbon monoxide, heavy metals, even radioactive polonium (for tobacco specifically). The problem with smoking isn't that we're misusing our lungs, it's that we're bringing a fairly large amount of toxic material into our bodies.

        I'm not worried about bone conduction, I feel that open ear is much safer than closed ear because I can eg hear a smoke alarm or hear a housemate fall and cry out for help. If there were evidence it caused brain damage or something then I would stop using them but I don't think there is. I try to regularly turn my volume down below where I can hear it and then turn it one click up to mitigate damage to my hearing. That's definitely a real risk but that's not specific to bone conduction.

  • By throw5 2026-03-151:553 reply

    How about in-ear earphones? They use silicone tips, right? Are there any known harmful effects of those?

    The study names brands like Bose, Panasonic, Samsung, and Sennheiser. What about Apple airpods? Anyone knows what's that made of and if they've got any harmful effects?

    • By lich_king 2026-03-152:34

      Silicone doesn't require plasticizers (because it's elastic on its own) or fire retardants (because it doesn't burn easily). The material itself is also considered biologically inert and is less affected by temperature, solvents, etc. So it's usually the best choice for stuff like that. The reason it's not as common is that it's more expensive and not as durable. It has relatively poor abrasion and cut resistance.

      But then, I wouldn't worry about headphones at all. You probably sleep on a mattress made from polyurethane foam that contains plasticizers and fire retardants in much greater quantities. The same goes for your car seats, and they off-gas a lot more when parked in the sun. You'd probably need to eat 1,000 earbuds to match that.

    • By nozzlegear 2026-03-152:391 reply

      Here's a link to the study, which lists the results of each individual device they tested toward the end: https://arnika.org/en/publications/download/2128_f40ae4eb2e6...

      AirPods were rated "green" across all three of their test categories.

      • By gnabgib 2026-03-152:431 reply

        Airpods weren't.. gen 2 (the only version, and Apple product they tested) were.

    • By andai 2026-03-152:001 reply

      Have they invented plastics that are good for your hormones?

  • By dialogbox 2026-03-151:39

    > "Daily use—especially during exercise when heat and sweat are present—accelerates this migration directly to the skin."

    How about the running shoes? That must have much more chemicals and adhesives although I don't have data for that.

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