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The researchers found an average of around 100 microplastic particles per liter in glass bottles of soft drinks, lemonade, iced tea and beer. That was five to 50 times higher than the rate detected in plastic bottles or metal cans.

"We expected the opposite result," Ph.D. student Iseline Chaib, who conducted the research, told AFP.

"We then noticed that in the glass, the particles emerging from the samples were the same shape, color and polymer composition—so therefore the same plastic—as the paint on the outside of the caps that seal the glass bottles," she said.

The paint on the caps also had "tiny scratches, invisible to the naked eye, probably due to friction between the caps when there were stored," the agency said in a statement.

This could then "release particles onto the surface of the caps," it added.

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[-] be_gt@lemmy.world 180 points 1 month ago

So nothing coupled to the glass but rather the cap having a extra plastic layer on the wet side.

[-] MrQuallzin@lemmy.world 123 points 1 month ago

Sounds like we found the issue, now it's just a matter of producers improving the caps

[-] ieatpwns@lemmy.world 65 points 1 month ago

Only if it doesn’t cut it to record profits

[-] lemerchand@sh.itjust.works 6 points 1 month ago

Only if it somehow increases profit. FTFY

[-] fluxion@lemmy.world 41 points 1 month ago

Nah ill just spend $50 to have a Congress member introduce a bill to make regulating microplastics illegal

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[-] Infinite@lemmy.zip 55 points 1 month ago

No, the paint on the outside.

[-] NoSpotOfGround@lemmy.world 27 points 1 month ago* (last edited 1 month ago)

Yes. So many people are misunderstanding this article... The microplastics are on the inside, in the drink, and they are bits of the paint from the exterior of bottle caps that stuck to the inside of other caps when the caps were all jumbled together in big bags before they were placed on the bottles.

[-] forrgott@lemmy.sdf.org 26 points 1 month ago

That would be far more intuitive, but it's not that - it's the painted logo on the outside.

[-] Karyoplasma@discuss.tchncs.de 72 points 1 month ago

Step 1: Invent plastic bottles

Step 2: Pocket the cash

Step 3: Things got bad? Outsource the clean-up to the end user in the form of recycling

Step 4: Increase prices to account for recycling

Step 5: Laugh as the idiots actually recycle your shit

Step 6: Throw the whole shebang in the ocean or in landfills

Step 7: Pocket some more cash

Step 8: Pat yourself on your shoulder. You've done some capitalism.

[-] daniskarma@lemmy.dbzer0.com 34 points 1 month ago* (last edited 1 month ago)

Title seems misleading.

As the micro plastics were found on the paint outside the bottle cap. It seems complicate that that ended on the drink itself. Unless you are licking the bottle cap it doesn't seem that relevant.

[-] iglou@programming.dev 31 points 1 month ago

No, the microplastics were found in the content of the bottles. The cap thing is where they come from. As a reply to you explained, the microplastic from the top of a cap is scratched by another cap and ends up on the bottom of yet another cap.

[-] Gobbel2000@programming.dev 22 points 1 month ago* (last edited 1 month ago)

The paint on the caps also had "tiny scratches, invisible to the naked eye, probably due to friction between the caps when there were stored," the agency said in a statement.

This could then "release particles onto the surface of the caps," it added.

Paint scratches off the outside, then sticks to the inside and makes it into the drink.

[-] Korhaka@sopuli.xyz 4 points 1 month ago

Landing on the outside surface though, how is it making it through the cap?

[-] pdqcp@lemmy.dbzer0.com 16 points 1 month ago

Caps aren't stored individually, they scratch each other all the way into the capping machine, see this cap feeder for example:

https://yewtu.be/watch?v=4717zbMCMHU
https://youtu.be/4717zbMCMHU

[-] creisel@lemmy.zip 14 points 1 month ago

Wait...we not licking bottle caps anymore?!

[-] Smoogs@lemmy.world 7 points 1 month ago* (last edited 1 month ago)

I think because there is a helix twist that glass would grind away the plastic every time it’s recapped. Hence why at the end of the article it is urging manufacturers to use air and alcohol to clean the cap before fitting it to the bottle. Additionally using something other than a plastic cap to reseal the bottle when being used. And especially not one with a helix requiring a twist. You can use a wine reseal which requires no twisting

[-] Bosht@lemmy.world 31 points 1 month ago

Man on the surface this reeks of inside payoffs. I guess the technicality is plastic caps on glass bottles?? Which seems weird and nothing I've ever seen. Unless they're referencing the seal on the inside of some metal caps on glass bottles? Either way, seems suspect. I'd assume that overall drinking from glass is safer, as with plastic on any timeline you're dealing with the plastic breaking down and leaching chemicals and micro plastics into the liquid, which wouldn't be an issue with glass.

[-] Infinite@lemmy.zip 48 points 1 month ago

Not plastic caps, plastic paint. The printing on bottlecaps is a polymer and it gets scuffed.

[-] NateNate60@lemmy.world 20 points 1 month ago

Odd. I would have thought that the paint, being on the exterior, wouldn't leak into the beverage contained inside the glass.

But apparently, they found that blowing air over the caps reduced the amount of detected contamination by 60 per cent. So it seems like an easy fix that manufacturers can implement inexpensively (literally just an electric fan)

[-] MotoAsh@lemmy.world 15 points 1 month ago

Or just not paint the caps, at least not with plastic.

[-] NateNate60@lemmy.world 9 points 1 month ago* (last edited 1 month ago)

There is a real reason that the caps are painted. Glass beverage bottles are usually stored in a crate and grabbed from the top, so the design on the lid is what restaurant or store employees used to distinguish what drink is contained within it. This allows employees to distinguish similar-coloured drinks (e.g. Coca-Cola vs Pepsi or two different brands of beer) just from looking down at the top of the bottle.

But there probably is a way to paint them without using plastics

[-] monogram@feddit.nl 5 points 1 month ago

Then stamp/engrave the caps paint isn’t needed

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[-] scrion@lemmy.world 7 points 1 month ago

Unfortunately, it's probably not going to be an electric fan, but compressed air. Even more unfortunately, compressed air turns out to be a major cost factor due to the cost of running compressors, which might prevent adoption.

The original paper mentions blowing the caps out with an "air bomb", which I'm pretty sure is a mistranslation stemming from the French term "Bombe d’Air Comprimé", i. e. an air duster, a can of compressed air. In an industrial setting, you'd use a compressor for this, naturally.

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[-] Cawifre@lemmy.world 14 points 1 month ago

The paint itself on the outside of the bottle cap. The ultra thin layer of (apparently polymer a.k.a. plastic) paint that make the cap not just metal colored.

[-] BigBenis@lemmy.world 22 points 1 month ago

For the people in the comments who either won't or seemingly can't read the article: The paint on the top of the caps is plastic-based and before they're put on the bottle they're stored in a big jumbled up pile where the paint chips off and coats the caps in tiny flakes. When the cap gets put on the bottle, the flakes on the bottom of the cap get washed off into your drink. Studies show that washing the caps first dramatically reduces the micro-plastic contamination.

[-] Agent641@lemmy.world 21 points 1 month ago

Just pour it from the glass bottle to the plastic bottle. Problem solved

[-] Numenor@lemmy.world 13 points 1 month ago

We just need glass caps then

[-] zaphod@sopuli.xyz 29 points 1 month ago

Or just unpainted aluminium caps.

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[-] creisel@lemmy.zip 11 points 1 month ago

When I was a kid they were made from metal

[-] SoleInvictus 11 points 1 month ago

When I was a kid they were made from cork.

[-] creisel@lemmy.zip 6 points 1 month ago

How are you still alive?🙈

[-] MonkderVierte@lemmy.zip 5 points 1 month ago

They are still made from cork.

[-] Shapillon@lemmy.world 11 points 1 month ago

In a bizarre twist, glass caps have been found to contain alarming levels of microdrink.

[-] Korhaka@sopuli.xyz 6 points 1 month ago* (last edited 1 month ago)

I quite like the swing tops with a small rubber ring that makes the seal. Easily reused too. Which is better than recycling.

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[-] Ledivin@lemmy.world 11 points 1 month ago

...do plastic bottles not have caps? I'm confused.

[-] baronvonj@lemmy.world 12 points 1 month ago

their caps are fully plastic, not painted metal. The non-screwtop metal caps need to be bent to release their grip on the bottle. That scrapes the paint off the metal cap.

[-] Damage@feddit.it 11 points 1 month ago

it's more likely that paint is scratched off by other caps, idk about metal caps but plastic ones are usually handled in bags, thrown into a cap feeder that aligns them and loads them into the capper. I expect metal caps to go through a similar process, and all that movement is bound to scratch it and send particles everywhere.

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[-] Evil_Shrubbery@lemm.ee 9 points 1 month ago* (last edited 1 month ago)

Ok, great find, we can simply switch the caps & solve the problem.
(The corps will do that, right??)

But I wander with such tests ... could there be any significant detection issues?

Did they have the proper equipment and processes? A methodological limitation to particle size maybe?
Coz some researches find higher concentrations than 100.

[-] UltraMagnus0001@lemmy.world 6 points 1 month ago

WTF. Guess I'm an android now, because I'm half plastics on the inside.

[-] FenderStratocaster@lemmy.world 4 points 1 month ago

Anyone drinking beer or soft drinks out of glass bottles probably isn't worried about micro-plastics.

[-] protist@mander.xyz 45 points 1 month ago

I like beer and would definitely prefer my beer not contain microplastics

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[-] cattywampas@lemm.ee 19 points 1 month ago
[-] NateNate60@lemmy.world 18 points 1 month ago* (last edited 1 month ago)

Parent commneter implies that people who consume soft drinks or alcohol aren't concerned about their health because these beverages are not healthy

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[-] BlueLineBae@midwest.social 12 points 1 month ago

What about kombucha? Ice tea? Water?!?! Would be nice to know that anything you consume regardless of how healthy or not doesn't contain micro plastics or other contaminants.

[-] Empricorn@feddit.nl 5 points 1 month ago

Ooo, we have a contender for Worst Take!

🏆

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this post was submitted on 23 Jun 2025
401 points (100.0% liked)

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