this post was submitted on 23 Jun 2025
372 points (93.3% liked)

science

19708 readers
2021 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
[–] [email protected] 14 points 2 days 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.

[–] [email protected] 6 points 2 days ago

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

[–] [email protected] 12 points 2 days ago (5 children)

We just need glass caps then

[–] [email protected] 31 points 2 days ago (1 children)

Or just unpainted aluminium caps.

[–] [email protected] 3 points 2 days ago (1 children)

I thought bottle caps were steel.

[–] [email protected] 4 points 2 days ago* (last edited 2 days ago)

they usually have a plastic lining inside them, or are painted.

[–] [email protected] 9 points 2 days ago

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

[–] [email protected] 4 points 2 days ago* (last edited 2 days ago)

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

[–] [email protected] 2 points 2 days ago

It actually exists for some brands of wine. It's annoying to open though.

[–] [email protected] 11 points 2 days ago (1 children)

When I was a kid they were made from metal

[–] [email protected] 9 points 2 days ago (1 children)

When I was a kid they were made from cork.

[–] [email protected] 5 points 2 days ago (1 children)

How are you still alive?🙈

[–] [email protected] 4 points 2 days ago (1 children)

They are still made from cork.

[–] [email protected] 3 points 2 days ago (1 children)
[–] [email protected] 3 points 2 days ago (1 children)
[–] [email protected] 2 points 2 days ago

Well yes, but they mostly switch to plastic as well for different reasons.

[–] [email protected] 16 points 2 days ago* (last edited 2 days 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.

[–] [email protected] 6 points 2 days ago* (last edited 2 days 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

[–] [email protected] 29 points 2 days 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.

[–] [email protected] 21 points 2 days ago* (last edited 2 days ago) (1 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.

[–] [email protected] 1 points 2 days ago (1 children)

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

[–] [email protected] 15 points 2 days 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

[–] [email protected] 14 points 2 days ago

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

[–] [email protected] 102 points 3 days ago (2 children)

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

[–] [email protected] 8 points 2 days ago

jajaajajajajajajajjjaaj

[–] [email protected] 18 points 2 days ago (1 children)
[–] [email protected] 13 points 2 days ago (1 children)
[–] [email protected] 11 points 2 days ago* (last edited 2 days ago)

Yea it's coarse and everywhere

https://youtu.be/2tLf1JO5bvE

load more comments
view more: next ›