Bildnachweis

Abb. 1, 2, 8–13, 15, 16 links : © DGUV
Abb. 3, 4, 6, 17: © Alfred Kärcher SE & CO. KG
Abb. 5, 7, 16 rechts, 19: © Otto Christ AG
Abb. 14, 18: © WashTec Claening Technology GmbH