ASTM E2197-17e1. Standard Quantitative Disk Carrier Test Method for Determining the Bactericidal, Virucidal, Fungicidal, Mycobactericidal and Sporicidal Activities of Liquid Chemical Germicides. 

Test accredited by ENAC (Spanish National Accreditation Entity).            

This test is designed to evaluate the ability of chemical agents to inactivate vegetative bacteria, viruses, fungi, mycobacteria and bacterial spores, on polished stainless steel disc supports, which represents a hard, non-porous surface environment.

The product to be tested is evaluated by inoculating at least five support discs (for each combination of test substance that you wish to analyze), with one or more of the following test organisms depending on the type of activity you wish to evaluate: Staphylococcus aureus (ATCC 6538), Pseudomonas aeruginosa (ATCC 15442), conidia of Trichophyton mentagrophytes (ATCC 9533), Candida albicans (ATCC 10231), conidia of Aspergillus niger (ATCC 64958), Mycobacterium terrae (ATCC 15755), spores of Bacillus subtilis (ATCC 19659) and spores of Clostridium sporogenes (ATCC 7955) and after drying the inoculated supports, they are treated with the product. In this method the evaluation of the chemical agents in wet wipes is not allowed since the test does not include any cleaning or rubbing action.

The method offers the possibility of incorporating an interfering substance incorporated in the suspension of the test organism, constituted by a mixture of tryptone, bovine serum albumin and mucin. The contact time, the temperature and the concentration of use, or indications on how to apply the product, should be indicated by the client.

The results obtained in the plate counts (CFU/disk) are averaged and converted to log10, thus determining the log10 of the reductions in the assay, a significant reduction that is evaluated by the Wilcoxon statistical method. In this way, the activity of the test substance is evaluated with respect to the controls.