Abstract: A pathological waste disposal unit (10) has a chamber (11) with a closeable cover (16) and a waste outlet (14) connected to a waste sump (20). A carrier (30) for waste bags (40) is mounted on a shaft (31), rotatable by an impellor (30), on which is directed high pressure water from nozzles (150). Water knives (70) cut open the waste bags (40) while the carrier (30) is rotating to release the waste (41) from the waste bags (40), to cause the waste to face the bottom wall (13) of the chamber (11) and flow through the waste outlet (14) to the waste sump (20). Safety interlock means prevent operation of the unit (10) while the cover (16) is raised and the opening of the cover (16) while the unit (10) is in operation.