Abstract: ON JUNE 18, 1992, A POSSIBLE LOW-LEVEL RELEASE OF ETHYLENE OXIDE GAS OCCURRED IN THE CENTRAL SERVICE DEPARTMENT OF NORTHRIDGE HOSPITAL MEDICAL CENTER, WHEN A CENTRAL SERVICE TECHNICIAN OPENED THE DOOR TO AN ETHYLENE OXIDE STERILIZER CHAMBER THAT WAS OPERATING IN THE AIR-FLUSHING MODE. THE STERILIZER'S CYCLE HAD FINISHED; HOWEVER, THE CHAMBER'S END-OF-CYCLE BUZZER WAS NOT WORKING, CAUSING CENTRAL SERVICE EMPLOYEES TO FORGET ABOUT THE LOAD. CONSEQUENTLY, NO ONE HAD STOPPED THE STERILIZER AND TRANSFERRED THE LOAD TO THE AERATOR AT THE END OF THE CYCLE. WHEN THE STERILIZER WAS NOT STOPPED AT THE CYCLE'S END, IT AUTOMATICALLY STARTED FLUSHING THE STERILIZER CHAMBER WITH CLEAN AIR. THE INCIDENT OCCURRED WHEN AN EMPLOYEE ON THE NIGHT SHIFT OPENED THE STERILIZER DOOR WITHOUT HITTING THE RESET BUTTON TO STOP THE AIR FLUSH AND LET THE STERILIZER RETURN TO ATMOSPHERIC PRESSURE. DUE TO THE LENGTH OF TIME THAT CLEAN AIR WAS RUNNING THROUGH THE STERILIZER CHAMBER, IT IS LIKELY THAT LITTLE OR NO ETHYLENE OXIDE WAS PRESENT WHEN THE DOOR WAS OPENED.