Abstract: A method and apparatus for comminuting and sterilizing infectious waste wherein the size reduction processes take place within the same sealed container within which the sterilization through vacuumization and saturated steam pressurization takes place. Between the vacuum cycle and the high-pressure steam cycle there is interposed an intermittent steam pressurization step to atmospheric pressure. The comminution of infectious waste material is carried out by a series of cutting, crushing and shearing elements which are arranged in a compact, stack-like fashion in a vertical arrangement with the bearing elements, clutch, gear and motor located outside the autoclave container and detachable therefrom, which allows ready access to the shredder stack which can be removed and exchanged in fully assembled fashion.