Which statement accurately describes autoclave sterilization and its standard parameters?

• A. Dry heat sterilization at 160°C for 2 hours
• B. Steam under pressure sterilizes biological materials; typical parameters are 121°C at 15 psi for 15–20 minutes
• C. Radiation sterilization using gamma rays
• D. Ethylene oxide gas sterilization

Answer: (B)

Autoclave sterilization relies on moist heat under pressure to rapidly and reliably kill microorganisms. The steam transfers heat very efficiently, and the added pressure raises the boiling point so you can heat the contents to a higher temperature without drying them out. A standard autoclave cycle uses steam at about 121°C (250°F) and 15 psi for around 15–20 minutes. This combination is proven to inactivate spores and most microbes, ensuring sterilization of instruments and other heat-tolerant items. The other methods described—dry heat at 160°C for 2 hours, gamma-ray radiation, and ethylene oxide gas—are different sterilization approaches that operate on different principles and have different temperature, time, and material compatibility requirements.