What is the recommended temp and time for sterilising sharp cutting instruments in a hot air oven?

• A. 60 mins - 170°C
• B. 180 mins - 150°C
• C. 240 mins - 125°C
• D. 120 mins - 140°C

Answer: (B)

Dry heat sterilization relies on hot air to kill microbes, so heat transfer is slower and you need a longer exposure to achieve sterility. Sharp cutting instruments are metal and tolerate this cycle, so the recommended approach uses a moderate temperature for a sufficient duration to ensure the heat penetrates everywhere and inactivates resilient organisms, including spores. Holding 150°C for about 180 minutes provides reliable sterility for these instruments in a hot air oven while minimizing the risk of damage from higher temperatures or too short a cycle. Other options—either shorter times at that temperature or higher temperatures for shorter times—may not guarantee complete sterilization or could increase risk to the instruments.