Simple Human Error Leads to Ethylene Oxide Release from Sterilizer

We received a call this morning that there had been an ethylene oxide release from a hospital sterilizer. Sterile processing staff at a large hospital placed a load into one of their three ethylene oxide sterilizers and started the cycle. A short while later the cycle aborted and while trying to identify the problem, one of the staff members unexpectedly opened the door.

The ChemDAQ ethylene oxide monitors immediately went into alarm and the two employees rapidly left the room. They and the rest of sterile processing evacuated the department until the monitors showed it was safe for them to return. In addition to the two women in the sterilization room, the other four workers in the department were all sent to the emergency room for evaluation. Fortunately, it appears that everyone was able to get out quickly enough that no-one suffered adverse symptoms from exposure to ethylene oxide.

The cause of the problem was later found to have been due to a simple human error. The manufacturer's service technician had been on-site earlier that day to do the regular preventative maintenance and when he was finished, he forgot to switch the sterilizer back from service mode to normal mode. In service mode the cycles times are short and the door locks are apparently disabled.

This incident shows the importance of being aware that even well designed, well maintained equipment can and sometimes does fail because of a simple human error that any of us could have made.

This blog has railed against the use of badges for ethylene oxide monitoring in healthcare as being ineffective. If these two workers had not evacuated after the sterilizer door was opened, then their exposure to ethylene oxide would have been considerably higher and it would have made no difference whether they were wearing a badge or not. Fortunately for the staff at this hospital, they were protected by a ChemDAQ monitoring system.