Abstract: Contaminated waste containers having one or more internally disposed waste compression frames which are locked into position within the containers by resiliently biased hold-down mechanisms oriented within guide channels which extend along the side walls of the containers. Each of the frame guide channels is selectively provided with a supplemental guide member which extends above the upper edge of the box in order to guide the compression frames when in an elevated position with respect to the box and channel caps are also provided to prevent waste from being forced into the upper portion of the channels during use.