apparatus and method for sterilizing and encapsulating contaminated waste particularly medical implement waste in which a volume of thermoplastic compound having a melting point temperature - calibrated at a value which corresponds substantially to the temperature at which all biological contamination is rendered sterile substantially on contact , and impregnating a space containing contaminated waste items with the liquid compound and thereafter cooling the mass to its solidified phase while containing it against protrusion of any waste item . two stage treatment of the waste is effected by utilizing a second calibrated thermoplastic having a lower melting temperature in a common deformable waste container with the first thermoplastic . the container is locked in a first geometry by means of the first thermoplastic so that preliminary heating liquefies the second thermoplastic to at least partially encapsulate and sterilize successive charges of waste , while simultaneously creating additional space in the container to receive the subsequent charges of waste . when the container is heated to a final elevated temperature it is released from its initial geometry by the liquefaction of the first thermoplastic to complete the final encapsulation and sterilization process .