Abstract: A closure is provided for a medical waste receptacle defining a receptacle opening positioned to receive medical waste. The closure includes a hood positionable adjacent the receptacle opening of the medical waste receptacle. The hood has a limiting surface at least partially defining an access opening facilitating access to an interior of the hood. A door is mounted at least partially within the interior of the hood. The door is mounted for movement about a pivot axis between an opened position and a closed position. In the opened position, a support surface of the door substantially permits access through the access opening of the hood, and in the closed position, the support surface of the door substantially prevents access through the access opening of the hood. The door is biased by gravity to rotate from the closed position toward the opened position. The support surface of the door in the closed position forms an angle at least about 100° with respect to a horizontal plane.