EN 1657: 2024. Quantitative suspension test for the evaluation of fungicidal or yeasticidal activity of chemical disinfectants and antiseptics used in the veterinary area. Test method and requirements (phase 2, step 1).

Test accredited by ENAC (Spanish National Accreditation Entity), for standard mandatory microorganisms and additionals, including under conditions of the BPR guidance.

This test for general disinfection products uses Candida albicans and Aspergillus niger (syn. Aspergillus brasiliensis) as obligate organisms for fungicidal activity and Candida albicans for yeasticidal activity. Other fungi may be used optionally. The test must be performed at a minimum temperature of 5°C and a maximum of 40°C, in 5°C increments. The contact time must be a minimum of 1 minute and a maximum of 120 minutes, in 30-second intervals up to 5 minutes, and in 5-minute intervals from 5 minutes to 120 minutes of contact time. Soiling conditions may be selected as low or high soiling. For the yeasticidal activity of teat disinfection with Candida albicans, the test temperature must be a minimum of 20°C and a maximum of 30°C. The contact times for pre-milking disinfection are a minimum of 30 seconds and a maximum of 3 minutes, and for post-milking disinfection, a minimum of 1 minute and a maximum of 5 minutes. The mandatory soiling conditions for pre-milking disinfection are 3 g/L of bovine albumin, and for post-milking disinfection, 10 g/L of reconstituted milk.

            The product should be tested for at least three concentrations including one in the non-active range and one in the active range (these last two concentrations are selected by the testing laboratory). The product can be tested by the dilution-neutralization method, or by the membrane filtration method. To consider the fungicide product a log reduction of 4 in the number of viable cells must be demonstrated.