Which sterilization method is preferred for heat-sensitive items?

• A. Ethylene oxide
• B. Steam (moist heat)
• C. Dry heat
• D. Gamma irradiation

Answer: (A)

Ethylene oxide is preferred for heat-sensitive items because it sterilizes at very low temperatures and can permeate complex packaging and materials without exposing them to heat or moisture. It works by alkylating DNA and proteins, effectively killing bacteria, spores, and viruses. While it requires careful handling due to toxicity and flammability and needs proper aeration to remove residues, its low-temperature, penetrative nature makes it suitable for plastics, electronics, and assembled devices that would be damaged by steam, dry heat, or radiation. Steam uses high heat and moisture, which can harm heat-sensitive items; dry heat requires even higher temperatures and longer times; gamma irradiation can alter some materials and needs specialized facilities.