Final answer:
Adequate sterilization in an autoclave at 15 psi is achieved at 121 °C with a typical exposure time of 20 minutes or more, ensuring steam contacts the material.
Step-by-step explanation:
The minimum temperature required to achieve adequate sterilization in an autoclave at 15 psi is 121 °C. At this pressure and temperature, a typical exposure time would be 20 minutes or more, dependent on the material's volume and nature. The steam must be in direct contact with the material, requiring containers to be loosely closed and instruments to be wrapped in materials like paper or foil to allow steam penetration.
Autoclaves are critical for moist-heat sterilization, effectively killing vegetative cells, viruses, and especially endospores, which can survive boiling temperatures. The design created by Charles Chamberland is still considered one of the most effective sterilization methods.