Final answer:
The cycle phase in an EO sterilizer when the cycle is held at the specified temperature and concentration for a specified time is known as the exposure phase, which is a key step in the ethylene oxide sterilization process, especially for heat-sensitive materials.
Step-by-step explanation:
The cycle phase in an EO sterilizer when the cycle is held at the specified temperature and concentration for a specified time is called the exposure phase. This phase is crucial in ethylene oxide (EO) sterilization processes, as it allows the sterilant, which is EO gas, to penetrate thoroughly and sterilize the items within. Since EO is used for gaseous sterilization, it is particularly effective for heat-sensitive items and materials that cannot tolerate the high temperatures and moisture of autoclave sterilization.
During the exposure phase, both temperature and EO concentration must be accurately controlled to ensure the effective sterilization of the materials, as well as adherence to safety regulations due to the carcinogenic and explosive nature of EO gas. Ethylene oxide sterilization is a form of cold sterilization, essential in various medical settings for the aseptic treatment of packaged materials.