Ethylene oxide gas is considered a cold sterilization technique because it sterilizes medical instruments at low temperatures without the use of heat. This method is ideal for heat-sensitive devices that cannot withstand autoclaving or dry heat. It effectively kills all microorganisms, including spores, by alkylating proteins and DNA. Unlike autoclaving or dry heat, which require high temperatures, ethylene oxide preserves the integrity and functionality of delicate surgical instruments. Its ability to sterilize without heat makes it indispensable in modern surgical practice.

Reference: Medical Microbiology, Murray et al., 9th Edition.