Period-after-opening symbol

It depicts an open cosmetics pot and is used together with a written number of months or years.

In the European Union, cosmetics products with a shelf life of at least 30 months are not required to carry a "best used before end of ..." date.

Instead, there has to be "an indication of the period of time after opening for which the product can be used without any harm to the consumer".

The EU Cosmetics Directive defines in Annex VIIIa the language-neutral open-jar symbol, which manufacturers should use to indicate this period.

The letter "M" is the initial for the word month not only in English, but also in Latin and many other European languages.