Which sterilization method is used by an autoclave?

Which sterilization method is used by an autoclave?

• A. Dry heat
• B. Ethylene oxide
• C. Steam under pressure
• D. Radiation

Answer: (C)

Steam under pressure is the sterilization method used by an autoclave. The autoclave blasts saturated steam into a chamber at high temperature and pressure, which rapidly denatures proteins and disrupts cellular structures of microorganisms, including spores. The moisture makes heat transfer much more efficient, so the items can be sterilized quickly and reliably at temperatures around 121°C (250°F) under about 15 psi for a standard cycle. This combination—moist heat plus pressure—is why autoclaves are effective for a wide range of heat-tolerant instruments and supplies. Dry heat sterilization relies on hot air and needs much higher temperatures and longer times, making it slower and less efficient for many items. Ethylene oxide is a gas sterilant used for heat- and moisture-sensitive items and has its own hazards and longer cycles. Radiation sterilization uses ionizing radiation and is not how an autoclave operates.

Steam under pressure is the sterilization method used by an autoclave. The autoclave blasts saturated steam into a chamber at high temperature and pressure, which rapidly denatures proteins and disrupts cellular structures of microorganisms, including spores. The moisture makes heat transfer much more efficient, so the items can be sterilized quickly and reliably at temperatures around 121°C (250°F) under about 15 psi for a standard cycle. This combination—moist heat plus pressure—is why autoclaves are effective for a wide range of heat-tolerant instruments and supplies.

Dry heat sterilization relies on hot air and needs much higher temperatures and longer times, making it slower and less efficient for many items. Ethylene oxide is a gas sterilant used for heat- and moisture-sensitive items and has its own hazards and longer cycles. Radiation sterilization uses ionizing radiation and is not how an autoclave operates.