Which of the following is an autoclave setting?

• A. 30 min at 250°F (10 psi)
• B. 20 min at 200°F (5 psi)
• C. 60 min at 320°F (20 psi)
• D. 5 min at 150°F (2 psi)

Answer: (A)

Autoclave sterilization relies on steam under pressure to reach a high temperature for a sufficient period, allowing penetration of instruments and killing of spores. The setting that uses a high temperature around 250°F and a substantial cycle time is the one that best fits this purpose. The 30-minute duration gives enough time for steam to fully penetrate and sterilize wrapped or dense loads, making it the most reliable option among the choices.

The other options either use too low a temperature or too low a pressure, which reduces steam effectiveness, or use a cycle that’s longer but at an extreme temperature that isn’t standard for routine sterilization. In short, this setting aligns with the principle of achieving sterilization through elevated temperature and adequate exposure time, making it the best choice.