Abstract: The disclosure relates to a process for the treatment of old paper without the use of biocides and chlorine compounds as well as with the virtual avoidance of hydrogen peroxide and/or peracetic acid with a total germ count of less than 1000 CFU/g and/or a surface germ count of less than 20 CFU/dm2, comprising the following process steps: a treatment of the pre-sorted, optionally pre-shredded, old-paper starting material in an environment containing water in order to activate the microorganism spores, a germination of the spores, a further processing of the old-paper starting material containing germinated spores, preferably in at least one separation stage in a generally known manner at temperatures above room temperature (20° C. to 70° C. [68° F. to 158° F.