A cleaning, disinfection, and indicator agent comprising awater--soluble permanganate, particularly for mixture with an agent forensuring an alkaline milieu having a pH value of at least 11,which, in addition to the water-soluble permanganate, contains afurther oxidizing agent, whose oxidation potential is above that ofmanganese VII to manganese VI, pH buffer substances, preferablyprimary and/or secondary alkali carbonates such as sodium carbonateand/or sodium hydrogen carbonate, as well as oxidation-resistantpolyphosphates. Furthermore, methods for cleaning, disinfecting,and monitoring the cleanliness of commercial and industrial plantsor plant components and the use of an agent according to thepresent invention as an indicator solution for ascertaining thecleanliness of commercial and industrial plants or plant componentsby ascertaining the intensity of the light emitted in the violetwavelength range by the solution are described.
