What is the correct temperature range for sterilization by dry heat?

• A. 300-320 F
• B. 340-360 F
• C. 360-380 F
• D. 320-340 F

Answer: (D)

Dry heat sterilization relies on hot, dry air to inactivate microorganisms, which transfers heat more slowly than moist heat. Because of this slower heat transfer, the validated cycle uses a higher temperature range for a longer exposure. The commonly accepted range is 320–340°F (160–170°C), with typical exposure times of about 1–2 hours depending on the load. This range ensures sterilization without excessive damage to most heat-stable instruments. Temperatures outside this range are not the standard dry heat sterilization cycle and either risk under-sterilization (too low) or potential damage or unnecessary exposure (too high).