Dry heat sterilization is characterized by which of the following?

• A. Kills by oxidation; takes 1-6 hours
• B. Uses steam under pressure
• C. Requires temperatures below 100°C
• D. Is effective for plastics and textiles

Answer: (C)

Dry heat sterilization relies on hot air to inactivate organisms, killing them primarily through oxidation. Because heat is transferred without moisture, it requires higher temperatures and longer exposure times to achieve sterility—usually on the order of about 1 to several hours depending on the load. It does not use steam under pressure. The process operates at temperatures well above 100°C, not below it, and is best suited for heat-stable items like metals and glass rather than many plastics or textiles, which can be damaged by prolonged high heat. This combination—oxidation-based kill and extended exposure at high temperatures—best fits how dry heat sterilization works.