This International Standard describes a test procedure for assessing the scratch resistance of organic paint coatings1), in particular paint coatings used in the automotive industry (i.e. for assessing their carwash resistance). Machine-based washing is simulated in the laboratory environment using a rotating brush and synthetic dirt. The test conditions have been designed to be as close as possible to the real conditions in a car-wash. If the test parameters are suitably chosen, the method can also be used for testing protective plastics films and plastics components.