The process comprises contacting surgical material with aqueous solution comprising 0.08-0.35 wt.% of peracetic acid (preferably 0.10-0.15 wt.%) and 1-10 wt.% of hydrogen peroxide (preferably 2-5 wt.%), in such way as to completely immerse surgical material in soaking tank containing 10-20 liters of aqueous solution as described above, for 20 minutes-1 hour, at ambient temperature. Independent claims are also included for: (1) a composition in the form of an aqueous solution as claimed and (2) the use of composition as claimed for disinfecting medical-surgical or dental materials.