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Hazardous substances found in all headphones tested by ToxFREE project

arnika.org

104 pointsmicroflash77 comments

https://arnika.org/en/publications/download/2128_f40ae4eb2e6...

https://www.theguardian.com/technology/2026/feb/18/hazardous...

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?

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.

> 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

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.

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

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.

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?

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.

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.

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

Tomato tomato.

Have they invented plastics that are good for your hormones?

A thing to remember is that bisphenols are everywhere, products/coatings/dyes/chemical processing, it's everywhere in the production and logistics of everything. I understand this concern with headphones specifically (heat + moisture + contact), but the stuff is in your clothes, your cooking utensils, your food packaging, the farm that grew your food, the feed troughs the cows eat out of etc.

with rigorous avoidance you can hope to reduce the amount in your body by like ~50% apparently but you can't get rid of it all because it's everywhere. unless you live off grid self-sustained and grow your own vegetables and have no plastic in your environment. so im not sure how much of a concern this study is or not.

> "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.

what's the proposed mechanism for them getting into the body? wearing while exercising?

From the article:

"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."

> There is no 'safe' level for endocrine disruptors that mimic our natural hormones

Can someone knowledgeable comment on this? It seems extreme to say there's no safe level.

There's a safe amount of cyanide (apple seeds), radiation (everywhere), safe speed of a bullet flying at you (if I just throw it gently at you) and so on. Even if the cyanide is technically poisoning you, the radiation from bananas is damaging you and the bullet I threw lightly grazed your skin, it's still safe in practical terms.

It's hard to define what 'safe' is.

The research is kind of hazy. Bisphenol-A has been shown to be a very very weak estrogen when measuring receptor binding affinity (about 37,000 times lower than human estrogen https://pmc.ncbi.nlm.nih.gov/articles/PMC2774166/#sec2), but has also been shown to be a potent stimulator in vitro for specific cell types (https://pubmed.ncbi.nlm.nih.gov/22227557/).

The lowest concentration of BPA that's been shown to be estrogenic according the second article is 0.1pMol/L which is around 230 picograms per litre of blood, or 1.1ng total for an average adult.

BPA's biological half life in humans is up to two to five hours depending on a range of factors (https://pmc.ncbi.nlm.nih.gov/articles/PMC2685842/), so taking the worst case you'd need to be continually exposed to around 2.5ng of BPA over a day.

So 'safe' as defined right now would be keeping the absorption below that 2.5ng per day threshold.

I don't know how how much BPA in plastics can transfer out per day, the research I've seen seems to indicate that unless it's a food container it's pretty minimal but I don't know enough to evaluate the quality of that research.

Your skin is also a pretty good barrier so only around 2.2% of any BPA on your skin can pass through in an ideal situation, so absorption from non-food sources is much lower (https://pmc.ncbi.nlm.nih.gov/articles/PMC9210257/)

The other problem is what do they replace BPA with? To be safer it would need at least as well studied as BPA, but often it seems like the 'safer' options are just not very well studied yet and could actually be worse.

> research I've seen seems to indicate that unless it's a food container it's pretty minimal

I use glass jars for storing food. One of the reasons is stuff like BPA leaching from the plastic to the food. Another is that it's much easier to have hundreds of identical jars to have a pretty and consistently filled kitchen cabinets. A third is that transparent plastic becomes less transparent after multiple washes with a sponge.

But what I hit "reply" for was to say that heating plays a role. So putting hot food inside a container is likely worse than putting something at room temperature in a container and then putting it in the fridge.

> 1.1 ng total for an average adult

Wow, that's so little. I wonder if malicious BPA poisoning cases have been reported. It's probably undetectable unless you search for it specifically.

> The other problem is what do they replace BPA with?

I remember reading that BPA could be replaced with BPB. Obviously it may be OK, but to a layman it's like saying "we no longer add rat shit to our food, now it's bat shit".

1.1ng is a very small amount, but the effect is really not that well understood. It’s definitely something we should minimise.

However it’s not a dangerous dose, it’s just the dose that produces detectable changes and we can detect really really small changes. The toxic dose is around 4g/kg body weight. So an average adult would need to consume over 300 grams of pure BPA to be poisoned by it.

Of course the answer is to use non-plastic containers, though the most common plastic used for food (PET - milk bottles, most soft drinks etc) don’t contain any BPA. It’s the reusable ones that do.

I have glass containers for food, though I do still use plastic ones for short term storage for things I won’t heat. Honestly this seems like the best answer, metal, wood and glass if you can.

> Can someone knowledgeable comment on this? It seems extreme to say there's no safe level.

Not a direct answer, but the article reports the maximum exceeding amount:

> Maximum concentrations reached 351 mg/kg, dramatically exceeding the 10 mg/kg limit originally proposed by the European Chemicals Agency (ECHA).

For things you put on your skin that could be absorbed, shouldn't the limit take into account the area touching your skin? If I lay on a bed containing 10 mg/kg BPA, I would absorb a lot more than if I touch a headphone. So maybe it should be mg/kg*m^2 or something?

The article is actually IMHO overly conservative. This kind of migration is not a theoretical risk, but well established. BPA is a small molecule, not covalently bound to the plastic. It absolutely goes into the skin. Heat, water, and acidity (sweat is slightly acidic) all accelerate the absorption.

Plus absorption through the skin is worse than oral. Because when you eat it your liver breaks a lot of it down. When it goes in the skin it bypasses all that.

But are the quantities significant?

Good point. And diving in I realize my fear was mostly unfounded. Compared to typical background exposure (what we can infer people are getting through other sources by looking at their urine) this is insignificant, except for the very worst headphones. The headline is unsurprisingly alarmist, because by their own data 68% have acceptably very low bpa. But the very few with the worst amounts drag up the arithmetic average to something scary sounding.

To estimate how much gets into the body https://oehha.ca.gov/sites/default/files/media/downloads/crn... Is a good reference. Interpolating from that, a typical pair of in-ear buds works out to something like a fraction of a nanogram per kg bodyweight per day, versus 30–130 ng/kg/day from background. So totally negligible. Even the worst case - highest measured concentration, assuming over ear headphones (much more contact area), and a hot sweaty workout, you’re looking at maybe 5ng/kg/day - still in the range of dietary background, but not good.

You may not be familiar with the prevalence of "hormone patches". Absorption through the skin is a common medical delivery method.

Counterpoint: these patches are used specifically for slow, controlled absorption of the medication in order to provide symptom relief over long durations. And even then, many drug patches use microneedles to overcome the skin's natural defense against absorption. Only the smallest of molecules can naturally pass through unbroken skin, and the fact that absorption is slow is the primary benefit of medicinal skin patches. They're used for things like hormonal therapeutic treatment or nicotine replacement because for those use cases, the slow, controlled absorption rate is beneficial for long-term relief.

I can’t stop myself from chewing on the little rubber cups that come in the ends of earbuds. I guess the slightly sweet synthetic taste is BPAs.

The dose makes the poison and modern detection techniques can be tremendously sensitive, I find these arguments unconvincing because mere detection presence isn't enough.

They do go into the levels of chemical found. From the article:

"Up to 351 mg/kg of bisphenols detected—35× higher than proposed EU limits"

There is far more data available in the orginal report:

https://arnika.org/en/publications/the-sound-of-contaminatio...

Why would they report on it if it was a safe amount and the study said "everything's fine"?

What were the models tested? This article has the list:

https://www.thestandard.com.hk/health/article/324892/Europea...

So looks like one broad conclusion is: the memory foam type of ear bud tip is normally toxic, so go for medical grade silicone replacements.

There are options available on major e-commerce sites. The ones I choose have a stainless steel nozzle and are supposed to enhance the sound reproduction.

Scare tactics for engagement. Fear is the best way to capture an audience.

If you're worried about your headphones, wait till you start thinking about the fabrics you're wearing that have plastic in them.

If I was going to try and limit exposure I'd start there, my headphones wouldn't be high on my list.

I find this kind of argument tiresome. If indeed you confidently know that a claim is fear mongering in bad faith, then the onus is on you to support your claims. Otherwise you're just adding to the noise. To wit, a perfectly reasonable response to you would be, "just another ignoramus claiming the result of a study is bad-faith fear-mongering without evidence". Or, another way to put it, is that precisely the same sentiment you express about the OP can be expressed about you, and the fact that you don't anticipate that makes your comment inherently suspicious to me.

BTW I don't know anything about the subject, so I mainly look for internal consistency and specific, accurate factual claims as evidence for credibility.

My comment about engagement farming wasn't directed to the OP but rather the groups publishing and funding such studies. Perhaps that's not even really the right term, but clout chasing also doesn't fit and I can't think of much else to describe it presently.

I'd much rather they focus their energy on the more ubiquitous sources of exposure to endocrine disrupting materials in our environment (plastic packaging, plastic bottles, can linings, mattresses and clothing for example).

There's no harm in sharing information and any awareness gained is always worthwhile. We're all free to draw our own conclusions at that point.

Apologies for the confusion on that aspect.

Honestly you should check every product you that comes in contact with your body against the OKEO Tex standard 100

While it would probably be preferable to reduce the plastic in your life in general (I’m converting as much as I can to platinum silicone from reputable sources) that might not be possible for everyone.

In the meantime, if you buy nylon or polyester clothing you should see what their policies are https://corporate.lululemon.com/~/media/Files/L/Lululemon/ou...

Previously submitted:

"Hazardous substances found in all headphones tested by ToxFREE project" : https://news.ycombinator.com/item?id=47058426

Hm. My kids listen to a lot of audiobooks with their headphones. These all seem to be mostly European brands. Is there a good, safe headphone brand for kids available in the US?

The point of the study is to raise awareness that there is a gap in regulation that should be addressed to ensure consumer safety when exposure from multiple devices can exceed the safety limits.

No single pair is “bad” for you at the moment.

So the action you can take is email/contact your elected officials so this can be on their radar for new policy.

According to the study, AirPods were rated "green" across all three of their test categories.

As were Bose, Sony and JBL (for most entries).. but the selection is a tiny fraction of brands x models (no premium items in the list: B&W, B&O, M&C, Pioneer, Grado).. unless you count Bose or Sony.. they have tens of models each, though.

OP was asking about their American kids, so I assumed they wanted something that would just work and wouldn't get them laughed at by their peers. Thus Apple :P

What do we do about this?

Are there BPA-free headphones on the market?

To add on to what others have already mentioned, the PDF has more details on bisphenols which paints a less dire picture than the press release.

1. There are no EU-wide regulations restricting on BPA concentrations in electronics devices.

2. The ECHA has proposed for limits is 10mg/kg which is also used for the OEKO-TEX Standard 100.

3. In the study's evaluation criteria, for parts to achieve a green rating for bisphenols, the concentration has be below 0.8mg/kg for parts touching the skin and below 10mg/kg for parts not touching the skin.

4. 69% of the tested samples achieved a green rating for bisphenols.

So while there is a gap in regulations ensuring a safe baseline for electronics, the majority of the tested headphones are doing okay as far as bisphenol exposure even under the proposed guidelines.

Annex 1 of the study lists the test results for individual brands/models. There are several, including Airpods, that get an all-green evaluation score.

Do you have a link to the study? How does that line up with "100% contained traces of hazardous chemicals"?

Here's the study: https://arnika.org/en/publications/download/2128_f40ae4eb2e6...

That URL is at the top of the page

Ah, doesn't show on the mobile app I'm using. I see it now on the website though.

I'm wondering the same. There are some master&dynamic models that are mostly made from metal/leather, but they're above my usual price range. I'm not really an audiophile, I'll settle for lower audio quality, but I'd prefer to wear one that doesn't have me constantly guessing whether I'm poisoning myself.

The PDF lists specific products and their results, Sony WH-1000XM5 look good, so do a few others. Purchasing a known-good model might be a good idea but I question how effective this would be, given potential variance in manufacturing processes between lots.

I use SteelSeries Arctis 1 which wasn't tested. The Arctis Nova 5 scored "red" for parts touching the skin though, so...

Wear over-the-ear headphones and use ear cushions or cushion covers that are made of fabric.

Appendix 1 extracted with Claude: https://docs.google.com/spreadsheets/d/139mTTtNsdanE9SEpmYaB...

To sort, click the Table 1 icon and select Create filter view.

This title reads like something that would come down the wire in 1984.

So like, we had it right with wood and leather after all?

After reading your comment, I've actually went to Google and looked up "wooden in ear headphones" and they actually exist! Fascinating!

Although, they still have silicone tips and the wood is probably treated with some kind of varnish for durability and aesthetics, so...

Quality silicone is probably the least worrying plastic material they could use considering it's used in implants and other medical applications.

The dose makes the poison. Paracelsus knew that 500 years ago already! Meanwhile in 2026 The Guardian publishes such articles every day (microplastics detected somewhere in irrelevant amounts, also water is wet).

The problem is we don't know what "irrelevant amounts" means, which is especially concerning because:

1. Microplastics are pervasive and would be very hard to remediate

2. They seem to bioaccumulate over years, and potentially even transmit intergenerationally

3. We have mechanistic evidence of them interfering with some rather critical biological processes, but processes that would yield chronic issues rather than acute ones

All of this makes it both very important and very difficult to understand the relationship between dosages and possible health effects.

> Maximum concentrations reached 351 mg/kg, dramatically exceeding the 10 mg/kg limit

When I read this sort of stuff, it feeds directly into my conspiracy theory about how people are being intentionally pacified using chemicals.

- Headphones marketed towards children. (children are most vulnerable as they are developing)

- Chemicals released "especially during exercise when heat and sweat are present." (teens who exercise and are fit/strong/threatening)

It's disturbing how prevalent forever chemicals are.

Every time I've seen some child's toy or device and the idea "This would be a perfect way to target children to disrupt their hormones" came to my cynical, paranoid mind... After a little bit of investigation, I found it's full of endocrine disruptors!

E.g. I bought a small inflatable swimming pool for my toddler son and I noticed how he was putting his mouth on the sides and I thought "Would be a perfect way to deliver endocrine disruptors to toddlers" - So I did some searching, contacted the manufacturer; surprise; it's full of phthalates but they claim 'within approved regulatory limits'!

Then I saw my son's toothbrush had some blue rubber behind to 'scrub the tongue'; it had some cartoon characters on it to appeal to children and I though to myself "That would be a perfect way to get some endocrine disruptors directly into children's mouths on a daily basis"... I did a search and guess what? Do I need to say it, you conspiracy theorist!?

Now this story about children's headphones...

Now consider all this in the context of declining sperm counts and media narratives which conveniently frame population control as the main solution.

I think one of the main problems is that regulations don't work. Under a capitalist system, the government cannot monitor everything that is being sold on the 'free market' or else it's not a free market anymore. The only way to have a functioning capitalist system is by getting rid of regulations and instead replace them with HARSH punishment. No more 'limited liability' bs! If a corporation does something bad; everyone should be fined, including the shareholders! You didn't know? Too bad! You should have done your research! I'm a dumb consumer and even I could figure out that the product contains endocrine disruptors!

It's just insane that we let it come to this. Bring back full liability! Just jail for executives and a fine for shareholders would help a lot.

There’s a discontinuity in this conspiracy theory: you haven’t explained how endocrine disruption pacifies the population (or anything else, besides disrupting their endocrine system).

As always, the more parsimonious answer is that plastic is cheap and that nobody is incentivized to determine the long term cost of usage/exposure. You don’t need a conspiracy to explain the outcomes here; profit motive suffices.

I know certain financial interests love this discontinuity because we can't discuss fully without getting into taboo subjects. I prefer to leave it to the reader to infer how hormonal dysfunction might lead to a passive demeanor.

> it feeds directly into my conspiracy theory about how people are being intentionally pacified using chemicals.

What is more likely? That there's a grand conspiracy involving thousands of people to chemically pacify the population. Or that products made with plastic are cheap and easy to make.

I don't know. I really wonder sometimes. For example:

Does adding an endocrine-disrupting 'tongue scraper' to children's toothbrush actually lower costs? Does this feature even add any value at all to the product? Why not clean the tongue with the bristles! The feature doesn't seem to justify the cost. All I can see is added marketing 'value'.

Also, people like to draw a distinction between "There is an intentional conspiracy by government officials to disrupt children's hormones" vs "Government officials know that children's hormones are being disrupted and they not only let it happen, they give the official seal of approval to the products, certifying their safety, when they are provably not safe in the aggregate if you look at population health statistics."

From my perspective, both cases are malicious and I don't see the point of trying to figure out which one is the case! It's a discussion of lesser evils and it seems like a deflection.

It's a conspiracy either way; in the second case, it's a conspiracy of neglect. A conspiracy of people getting paid to do nothing about a problem that they're claiming to be preventing! In the very best light, it's a false solution which acts as a placeholder for a real solution.

> The feature doesn't seem to justify the cost. All I can see is added marketing 'value'

You think marketing value does not justify added costs?

> Why not clean the tongue with the bristles!

Same reason you don't use the bristles to brush your hair. It doesn't work as well as a solution made for that purpose.

> Government officials know that children's hormones are being disrupted and they not only let it happen

Government officials define exact safety thresholds and rules for product materials to prevent health problems. That's why today we are debating trace amounts of something in plastic instead of lead in paint causing nationwide crime spikes and cognitive decline.

> When I read this sort of stuff, it feeds directly into my conspiracy theory about how people are being intentionally pacified using chemicals.

Why pacified? I don't really have "conspiracy theory" about this (as in, I don't think there's a group doing it intentionally), but I've idly wondered if the state of the world could be partially explained by things like microplastics and plastic chemicals leeching into our bodies. Kind of like the leaded gasoline/increased crime hypothesis.

PDF: https://arnika.org/en/publications/download/2128_f40ae4eb2e6...

Better article: https://www.theguardian.com/technology/2026/feb/18/hazardous...

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