Peracetic acid is a frequently used disinfectant. The Reflectoquant® Peracetic acid test strips are suited for the selective determination of the peracetic acid concentration in aqueous solutions and to check for the absence of peracetic acid after rinsing processes, also in cases in which hydrogen peroxide is present. Peracetic acid reacts with a phenol derivative to form a violet dye that is determined reflectometrically on the RQflex®. For pre-testing a sample in an economic and quick way to estimate the peracetic acid concentration and a possible dilution factor prior to using this quantitative method we recommend our semi-quantitative MQuant® test strips for peracetic acid.