Certification Board for Sterile Processing and Distribution (CBSPD) Sterile Processing Technician Practice Exam

What is the primary function of humidity in the sterilization process using ethylene oxide?

1. To increase pressure

2. To enhance EO penetration

3. To cool the environment

4. To reduce EO concentration

The correct answer is: To enhance EO penetration

The primary function of humidity in the sterilization process using ethylene oxide (EO) is to enhance EO penetration into the materials being sterilized. Ethylene oxide is a gas that acts as a sterilant and is particularly effective at killing microorganisms, including bacteria and spores. However, its ability to penetrate packaging materials and reach all surfaces of instruments is crucial for effective sterilization. Humidity plays a significant role in this process. When moisture is present, it helps EO to more easily permeate the materials undergoing sterilization. This improved penetration is vital because it allows the gas to contact all surfaces, ensuring complete sterilization throughout. Adequate moisture levels also facilitate the chemical reactions necessary for the sterilization process, contributing to the effectiveness of EO as a sterilant. In contrast, increasing pressure, cooling the environment, or reducing EO concentration do not have the same critical impact on the effectiveness of the sterilization process as humidity does. Thus, enhancing EO penetration through proper humidity levels is key to achieving successful sterilization outcomes.