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.
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.
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.
Paint scratches off the outside, then sticks to the inside and makes it into the drink.
Landing on the outside surface though, how is it making it through the cap?
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
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
Wait…we not licking bottle caps anymore?!