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.
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.
So this study only applies to glass bottles with plastic painted metal caps? Not unpainted metal caps or full plastic ones?
That is my impression. To be honest, I don’t think I’ve ever seen a glass bottle with a plastic cap. And I can’t really recall seeing what looked like unpainted metal caps except for homebrew stuff (and even then, it might be painted to what we think unpainted should look like).
Had those standing around, although I am not enirely sure the metal one isn’t coated.
Ok, I seemed to have forgotten about the existence of non-beverage glass bottles when looking at this post. I was only thinking of like soda, beer, and wine glass bottles.
Those are beverages (cider snd water respectively), I am unsure how you got to non-beverages?
I don’t recognize either brandings and they looked like sauce bottles (like varieties of vinegar, seed oils, marinades, etc). 🤷
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.