What autoclave temperature is commonly used for sterilization?

• A. 100 C
• B. 121 C
• C. 140 C
• D. 180 C

Answer: (B)

Sterilization with an autoclave relies on moist heat under pressure. The standard setting is 121°C (250°F) with steam at about 15 psi. This combination reliably denatures proteins in microorganisms, including spores, given a typical exposure time, making it the common choice for routine sterilization.

Boiling at 100°C without pressure isn’t enough to guarantee sterility, which is why that temperature isn’t used for autoclave cycles. Higher temperatures like 140°C or 180°C are not the normal autoclave conditions for standard sterilization; they’re used in other methods or special fast cycles, but 121°C is the usual standard.