As of July 3, a requirement went into effect in the European Union to market only plastic bottles with the cap that remains attached by one flap, aka a tethered cap. The requirement is contained in a 2019 European directive on reducing the incidence of plastics, which banned, as of July 2021, the sale of certain disposable plastic products such as cutlery, picnic plates, single-use straws, cotton buds, and plastic balloon sticks.

The goal of the caps rule is to make sure that cap and bottle are thrown away at the same time, hopefully in the recycling bin, and so that the caps are not dispersed into the environment. Indeed, caps and lids are among the single-use plastic items that pollute European beaches the most, and are increasingly a problem because of their long decomposition times.

For years now, companies in the industry have begun to adapt to the new rule, with the result that in many European countries, including Italy, caps attached to bottles have already been on the market for some time.