DIN 4102, which described the fire protection classes for Germany until 2001 and was widely used in all of Europe, and EN 13501, which is now the European standard, use the same four main classes. However, the tests differ between the two standards in the way they are carried out. In addition, the test procedure according to EN 13501 has been extended to include criteria such as smoke development and dripping behaviour. Smoke development is indicated with the abbreviation ‘s’ (for smoke) and dripping behaviour with the abbreviation ‘d’ (for droplets).