Since the new rules stipulated by the governments of the Federal States came into force, everyone who uses public transport must wear a medical mask. The new rules in Hamburg have been in force since 22.01.2021, in Schleswig-Holstein and Lower Saxony since 25.01.21. Simple cloth masks or bandanas and scarves are then no longer enough.
The prescribed medical masks include surgical masks (these are usually blue and white), but also masks of the KN95/N95 and FFP2 standard (without an exhaling valve).
Mandatory wearing of masks applies on all HVV public transport and in the areas of stops/stations where you are required to have a ticket.