EN 17422: 2022. Quantitative surface test for the evaluation of teat disinfectants in the veterinary area. Test method and requirements (phase 2, step 2).

Test accredited by ENAC (Spanish National Accreditation Entity).

The draft standard EN 17422: 2022 specifies a surface test method and requirements for establishing whether a teat disinfectant shows bactericidal activity. 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.

The test method described by the draft standard EN 17422: 2022 is based on standard EN 16437 (Quantitative surface test for the evaluation of the bactericidal activity of chemical disinfectants and antiseptics used in the veterinary area on porous surfaces without mechanical action - Method and test requirements, phase 2/step 2), but takes into account the practical conditions of application of the products used for teat disinfection, adapting the conditions that may influence their activity in the practical application, including the test surface, contact time and temperature.

The laboratory test according to EN 17422: 2022 document uses human synthetic skin as test surface, the microorganisms Escherichia coli and Staphylococcus aureus, a temperature of 30°C, and contact times and interfering substances that vary depending on the whether the test product is a pre-milking or a post-milking disinfectant. For pre-milking disinfection, the test uses a contact time of a minimum of 30 seconds and a maximum of 3 minutes, and bovine albumin as interfering substance. In the test for post-milking disinfection, the minimum contact time is 1 minute and the maximum 5 minutes, whereas milk powder is used for the simulated soiling. The product must be tested at least at three concentrations including one in the non-active concentration range and another in the active concentration range (these last two concentrations are selected by the testing laboratory because they correspond to the internal controls of the test). To consider the test product as bactericidal, it shall demonstrate a 3 decimal log reduction in the bacterial counts for pre-milking disinfectants and a 4 decimal log reduction for post-milking disinfectants.