A mobile self-contained apparatus and process for grinding, grating, macerating, chemically disinfecting, and drying infectious waste material. A trailer (10) contains a hopper (27), a grinder/grater (28), an enclosed conveyor system, drying and filter apparatus, and sources of power, chemical disinfectant, and fresh water. Bagged infectious waste material in a cart is lifted and dumped into the hopper, sprayed with a sodium hypochlorite disinfectant solution, fed to the grinder/grater, ground, grated, and macerated into small particles of confetti-like material, sprayed again, immersed in the disinfectant solution, conveyed by an upwardly inclined screw conveyor (34) and thoroughly mixed therein, dried, passed into a vertical screw conveyor (47), and passed to a discharge screw conveyor (50) which discharges the dry confetti-like material. The enclosed system operates under negative pressure produced by a suction fan that draws the air within the system through a HEPA filter to remove chemical fumes, airborne dust, odors and bacteria.