[sixtyj]

In micro and nano scale things can behave differently so it is quite hard to decide what to ban.

Plastic straws and caps attached to bottles - reason was that there are too many of them and people don’t behave properly and don't throw things in the trash and throw them on the ground where they are eaten by animals. At some British beach they counted >100 caps per 100 m (or something similar, it was a surprising number).