OSMT (Ontario Society of Medical Technologists) Practice Exam

What does the autoclave use in terms of pressure and temperature for sterilization?

1. 12 psi at 115C

2. 15 psi at 112C

3. 112 psi at 120C

4. 15 psi at 121C

The correct answer is: 15 psi at 121C

The correct answer is based on the standard conditions required for effective sterilization using an autoclave. An autoclave uses saturated steam under pressure to achieve sterilization, and the most widely accepted pressure and temperature combination for this process is 15 psi at 121°C. At this temperature, the steam reaches an energy level sufficient to kill a broad range of microorganisms, including bacteria and spores, ensuring that the sterilization process is thorough. This specific combination of pressure and temperature is critical because the temperature of 121°C is the minimum effective temperature required to denature proteins and effectively disrupt cellular processes in pathogens. Maintaining the pressure at 15 psi helps increase the boiling point of water, allowing the steam to retain heat and penetrate thoroughly into all surfaces of the items being sterilized. The duration of exposure is also an important factor; sufficient time at this temperature is essential to ensure that sterilization is achieved. In contrast, the other options present different temperatures and pressures that do not meet the recognized standards for sterilization with an autoclave, thereby underscoring the importance of using the correct parameters for safe and effective medical practices.