this post was submitted on 23 Jun 2025
371 points (93.2% liked)

science

19678 readers
566 users here now

A community to post scientific articles, news, and civil discussion.

rule #1: be kind

founded 2 years ago
MODERATORS
 

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.

top 50 comments
sorted by: hot top controversial new old
[–] be_gt@lemmy.world 161 points 2 days ago (3 children)

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

[–] MrQuallzin@lemmy.world 117 points 2 days ago (4 children)

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

[–] ieatpwns@lemmy.world 62 points 2 days ago (1 children)

Only if it doesn’t cut it to record profits

load more comments (1 replies)
[–] fluxion@lemmy.world 41 points 1 day ago (2 children)

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

load more comments (2 replies)
[–] Signtist@lemmynsfw.com 20 points 1 day ago

Ha! Good one.

load more comments (1 replies)
[–] Infinite@lemmy.zip 53 points 2 days ago (1 children)

No, the paint on the outside.

[–] NoSpotOfGround@lemmy.world 24 points 1 day ago* (last edited 1 day 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 25 points 2 days ago

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

[–] LovableSidekick@lemmy.world 111 points 1 day ago (2 children)

In a bizarre twist, plastic bottles have been found to contain alarming levels of microglass.

[–] creisel@lemmy.zip 21 points 1 day ago (1 children)
[–] Hupf@feddit.org 16 points 1 day ago (1 children)
[–] creisel@lemmy.zip 11 points 1 day ago* (last edited 1 day ago)

Yea it's coarse and everywhere

https://youtu.be/2tLf1JO5bvE

[–] copdeb@crazypeople.online 8 points 1 day ago

jajaajajajajajajajjjaaj

[–] Karyoplasma@discuss.tchncs.de 69 points 2 days ago (1 children)

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.

[–] bollybing@lemmynsfw.com 39 points 1 day ago

You forgot the step where they invent a logo that looks almost the same as the recyclable logo and stick it on all plastics but it doesnt mean its recyclable but instead just says what kind of plastic it is.

[–] MTK@lemmy.world 47 points 2 days ago (2 children)
[–] Donjuanme@lemmy.world 19 points 1 day ago (3 children)

As someone in a cork industry, you really don't want that.

[–] MTK@lemmy.world 27 points 1 day ago (1 children)

What is this teasing? Elaborate.

[–] londos@lemmy.world 8 points 1 day ago (1 children)

It takes a lot of effort to soak the corks.

[–] Agent641@lemmy.world 12 points 1 day ago (1 children)

Its really hard to soak my own cork, so I just get my girlfriend to soak my cork instead.

[–] robocall@lemmy.world 8 points 1 day ago (2 children)

I also get this guy's girlfriend to soak my cork

load more comments (2 replies)
[–] piranhaconda@mander.xyz 12 points 1 day ago (1 children)

Care to expand on why? I've had corks dissolve and break if I didn't finish the drink quickly enough, just on liquor bottles that went unused for a year or so. Any other reason?

[–] ramielrowe@lemmy.world 30 points 1 day ago (1 children)

Slightly educated guess. True organic cork is produced by cutting the bark off specific trees. There are limited climates it grows. I would guess the scale with which we produce bottled drinks would require significantly more trees and labor that we currently have. And thus cork prices would skyrocket.

load more comments (1 replies)
load more comments (1 replies)
[–] 6nk06@sh.itjust.works 9 points 1 day ago

Corka Cola.

[–] Bosht@lemmy.world 26 points 2 days ago (3 children)

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 2 days ago (3 children)

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

[–] NateNate60@lemmy.world 18 points 2 days ago (2 children)

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 day ago (1 children)

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

[–] NateNate60@lemmy.world 9 points 1 day ago* (last edited 1 day ago) (5 children)

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

load more comments (5 replies)
[–] scrion@lemmy.world 8 points 1 day 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.

load more comments (2 replies)
[–] Cawifre@lemmy.world 13 points 2 days 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.

load more comments (1 replies)
[–] Agent641@lemmy.world 21 points 1 day ago

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

[–] BigBenis@lemmy.world 20 points 1 day 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.

[–] daniskarma@lemmy.dbzer0.com 15 points 1 day ago* (last edited 1 day ago) (4 children)

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 day 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 20 points 1 day ago* (last edited 1 day ago) (2 children)

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.

load more comments (2 replies)
[–] creisel@lemmy.zip 14 points 1 day ago

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

load more comments (1 replies)
[–] Numenor@lemmy.world 13 points 1 day ago (5 children)

We just need glass caps then

[–] zaphod@sopuli.xyz 31 points 1 day ago (2 children)

Or just unpainted aluminium caps.

load more comments (2 replies)
[–] creisel@lemmy.zip 12 points 1 day ago (1 children)

When I was a kid they were made from metal

[–] SoleInvictus@lemmy.blahaj.zone 9 points 1 day ago (5 children)

When I was a kid they were made from cork.

load more comments (5 replies)
load more comments (3 replies)
[–] Ledivin@lemmy.world 11 points 2 days ago (1 children)

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

[–] baronvonj@lemmy.world 10 points 2 days ago (7 children)

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 day 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.

load more comments (6 replies)
load more comments
view more: next ›