EN 1656: 2019. Quantitative suspension test for the evaluation of bactericidal 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, and under specific conditions of the BPR guidance.

This standard uses four mandatory organisms in the test for general disinfection products (Pseudomonas aeruginosa, Proteus hauseri, Staphylococcus aureus and Enterococcus hirae). The interfering substance can be chosen for low level or high level dirty, and a temperature between 5 to 40ºC (at 5ºC interval). For mammary gland teat disinfection products, the standard uses three obligatory microorganisms (Escherichia coli, Staphylococcus aureus and Streptococcus uberis), a mandatory interfering substance for pre-milking disinfection (bovine serum albumin) and post-milking disinfection (skim-milk), and a mandatory temperature between 20ºC and 30ºC (5ºC interval). The mandatory time for general disinfection products is between 1 a 120 minutes, and for teat pre-milking disinfection between 30 secs and 3 minutes, and for post-milking disinfection products is between 1 and 30 minutes (30 secs to 5 minutes at 30 sec intervals, and from 5 to 120 mint at 5 minutes, intervals). Additional and optional contact times of 1, 5, 15 or 60 min, as well as additional and optional temperatures of 4, 20 or 40°C may be used. The product should be tested at three mandatory concentrations to include one concentration in the non-active range and one in the active range. The highest concentration of product that can be tested is 80%. The test may be performed by the dilution method or by the membrane filtration method. To consider the bactericidal product, a log reduction of 5 in the number of viable cells must be obtained.