CCI Certified Perioperative Nurse (CNOR) Practice Exam

The main idea is that after sterilizing with ethylene oxide, you must remove the leftover gas and its byproducts to keep people safe. Ethylene oxide is toxic and a known carcinogen, so an aeration phase is used to purge the load by circulating air through the chamber and around items. This off-gassing process speeds the removal of EO and any byproducts, reducing residual levels to what’s deemed safe before the items are handled or used.

A mechanical aerator works by pushing or circulating air through the sterilization chamber and around every item, sometimes with controlled heat or humidity to optimize how quickly EO dissipates. The goal is to meet safety standards for residual EO, protecting staff and patients from exposure.

Removing moisture, speeding up sterility validation, or preventing equipment corrosion are not the primary purposes of this aeration step. Moisture removal is more about drying after certain sterilization methods, sterility validation is a separate process, and corrosion isn’t the central safety concern addressed by aeration.