Founded in 1922 as a Hamburg paint and varnish factory, Rudolf Hensel develops and manufactures reactive fire protection coatings for steel, timber, concrete and cables, plus HENSOMASTIK penetration-seal and joint materials, exclusively at its Börnsen plant near Hamburg. The HENSOTHERM 421 KS steel system carries European Technical Assessment ETA-20/1228 with CE marking and the German allgemeine Bauartgenehmigung Z-19.51-2313, with Z-19.51-2349 covering steel tension members, assessed to DIN EN 13381-8 and DIN EN 13501-2. The company trains and authorises applicators of its systems.