An alternative to disposable masks are RUB masks from the Unishop.

Corona
Starting in July, masks will be compulsory in all public indoor areas

At the same time, most of the entrances to the buildings on campus will be reopened.

Wearing a mouth-nose mask will be mandatory in all public areas – such as corridors or social rooms – in the RUB buildings from 1 July 2020. There will be signs to that effect at all entrances to the buildings. Also from 1 July, the buildings will again be accessible via most of the* entrances and within the usual opening hours. Both measures are implemented as a result of the government gradually lifting the coronavirus lockdown.

*In an earlier version of the article, the word "all" was used at this point. In fact, there are some exceptions on the campus and especially in the outside properties, such as the "Musische Zentrum" or the Blue Square.