A cassette handling system for sterilant filled cassettes employs RFID or other electromagnetic signal technology to track the cassettes. A method for tracking the sterilant cassettes includes the steps of reading for the presence of a cassette within a cassette processing area of the sterilizer by transmitting a non-optical electromagnetic signal between the cassette and a receiver on the sterilizer, via the electromagnetic signal transmitting identifying information between the cassette and the receiver, and verifying that a proper cassette is loaded into the sterilizer based upon the identifying information.