Relevance and methodology. The results of laboratory studies of solutions of disinfectants Penox-1 and Penox-2, carried out on rough tests surfaces made of concrete, wood and metlakh tiles, against Mycobacterium (strain B-5) and Bac. cereus spores (strain 96) are presented. Experiments were carried out to establish the modes of disinfection of Penox-2 in a comparative aspect with solutions of Penox-1. For protein protection of the test cultures, horse blood serum was applied to the test surface, at the rate of 0.5 g/100 cm2. When developing disinfection modes, contaminated rough test surfaces were placed horizontally and vertically. Disinfection of the test surfaces was carried out by the method of wet disinfection, at the rate of 0.5 l/m2, at exposure 1; 3 and 24 hours. The treatment was carried out twice with an interval of 60 min. All studies were carried out in 3-fold repetition. The criterion for the effectiveness of the agent in the disinfection of surfaces is 100% death of test cultures.Results. It was found that with a single irrigation with solutions of the Penox-1 preparation, disinfection of test surfaces made of concrete, wood and metlakh tiles contaminated with mycobacteria and Bac. cereus spores was not achieved. Disinfection of the test surfaces from mycobacteria occurred with double irrigation, exposure for 24 hours, at the rate of 1 l/m2. Double irrigation of Bac. cereus spores did not result in decontamination of test surfaces. At the same time, the addition of chloramine B to the composition of the preparation Penox-2 at a concentration of 0.5–3.0% led to the disinfection of test surfaces from mycobacteria and Bac. cereus spores respectively after 1 and 3 hours, at the rate of 0.5 l/m2, with single irrigation.