This procedure specifies a test method and the minimum requirements for bactericidal activity of teat disinfectants that form a homogeneous, physically stable preparation when diluted with hard water - or in the case of ready-to-use products - with water. This method applies to teat disinfectants that are used on teat skin without mechanical action as pre-milking and/or post-milking teat disinfectants in the veterinary area - i.e. in the breeding, husbandry, production, veterinary care facilities, transport and disposal of all animals except when in the food chain following death and entry into processing industry. NOTE 1 The method described is intended to determine the activity of commercial formulations under the conditions in which they are used. NOTE 2 This method corresponds to a phase 2 step 2 test. NOTE 3 Two types of synthetic skin were assessed in a ring trial with no significant difference in performance. One has been chosen as the test surface because it is commercially available. Other synthetic skins can become available and can be used if it shown that they give comparable results to the one referenced in this standard.