Quantitative test method for the evaluation of bactericidal, yeasticidal, fungicidal, tuberculocidal and/or mycobactericidal activity on non-porous surfaces with mechanical action employing wipes in the medical area (4- field test). Test method and requirements (phase 2, step 2) (EN 16615: 2026 Standard).
Test accredited by ENAC (Spanish National Accreditation Entity), for standard mandatory microorganisms and additional microorganisms, under the conditions of de BPR guidance for PT2, PT3 and PT4, and for the four indicated viruses under internal procedure.
Test with the certificate of Good Laboratory Practices (GLPs).
This is a carrier test to know if one chemical disinfectant for use on surfaces applied with wipes shows bactericidal, yeasticidal, fungicidal, tuberculocidal and/or mycobactericidal activity. The test product must provide a homogeneous mixture, physically stable when diluted in hard water, or with distilled water for products ready to use. The product is used on non-porous surfaces where disinfection is medically indicated, including hospitals, community medical facilities and dental institutions, clinics of schools and kindergardens and nursisng homes, and can occur in the workplace and in the home. The test surface is marked with 4 squares in a row and test field 1 on test surface is inoculated with the test suspension of test microorganism and the inoculum is left to dry. A wipe is soaked with 16 mL of the test product at the concentration requested for 30 minutes (other volumes and soaking times are allowed with deviations) or a pre-impregnated wipe is used. The test surface is wiped with the soaked wipe across the four marked test fields and wiped back to the starting point. The test surface is maintained at the temperature and for the contact time requested by the client. Microorganisms, temperature, soiling and contact times are employed as requested by the manufacturer. For bactericidal activity the test must include Staphylococcus aureus, Enterococcus hirae and Pseudomonas aeruginosa; for yeasticidal activity Candida albicans; for fungicidal activity Candida albicans and Aspergillus brasiliensis; for tuberculocidal activity Mycobacterium terrae; and for mycobactericidal activity Mycobacterium terrae and Mycobacterium avium. Test temperature must be selected between 4 ºC and 30ºC (in the range 21,5± 3,5 ºC for test performed at room temperature). Contact time must be at least 1 minute and no longer than 60 minutes (from 1 to 5 min at intervals of 1 min and from 5 min to 60 min at intervals of 5 min). Interfering substance for clean conditions is 0,3 g/L bovine albumin, and for dirty conditions is 3 g/L bovine albumin plus 3,0 mL/L erythrocytes.
In parallel with the test, a water control test with a wipe soaked with hard water is performed to ensure that the test microorganisms are spread on the 4 test fields, together with two drying controls (after drying of the inoculum and after the contact time). At the end of the contact time, the tests microorganisms are recovered from each test field, the number of surviving test microorganisms in each sample is determined and the reduction is calculated by comparing the results of the drying control after the contact time and the results obtained with the product. In order to show bactericidal activity, the product must demonstrate a reduction of 5 log in test field 1 and an average ≤50 CFU in test fields 2 to 4 for each test bacteria; and for yeasticidal, fungicidal, tuberculocidal and mycobactericidal activity, the product must demonstrate a reduction of 4 log in test field 1 and an average ≤50 CFU in test fields 2 to 4 for each test microorganism. For all claims, a minimum of 2 test runs must be performed. One first run with 2 concentrations to include one concentration in the active range and one concentration in the non-active range. For pre-impregnated wipes or ready-to use-wipes which cannot be diluted, fist run must be performed with 2 contact times, the non-active range has to be shown with a shorter contact time. If for testing the product the lower contact time is selected, 1 min; the 5 min contact time must be tested in addition. In the second run, the most resistant test organism from each claim must be selected and tested in two carriers with only one active concentration or active contact time.
To perform the test, ready-to-use wipes or liquid disinfectant products whose application requires mechanical action can be sent. For a basic test (two concentrations/ contact times for pre-impregnated wipes, a test temperature and one selected soil conditions) for determining each activity, a minimum of 20 wipes or 400 mL of liquid disinfectant product is required. It is always recommended to send a higher quantity of samples in case a result needs to be confirmed.