An apparatus for processing biomedical waste comprises a waste input container having an input door in a top thereof and an output door in a bottom thereof. A shredder is mounted under the output opening and is operative to shred waste to a desired maximum size. A processing chamber is located under the shredder such that, when the output door is open, solid waste deposited in the waste input container passes through the output opening and through the shredder, and shredded waste drops into the processing chamber. Ozone gas is directed into the processing chamber, and an ozone indicator indicates ozone concentration. Exhausts are selectively operative to exhaust the atmosphere from the processing chamber and waste input container.