Heat is the best and most used sterilization agent and pressurized, saturated water vapor is the most efficient method of heat transmission. That is why steam sterilization reduces the time and the temperature needed for the treatment: at 134℃ an exposure of only 4 minutes is sufficient, at 121℃ a time of 15 minutes is enough. In addition, steam sterilization creates no toxic or dangerous residues on objects and does not damage instruments (provided that they can withstand the temperatures reached).
Disinfection destroys all the micro-organisms present in a given environment apart from spores: an object that has been disinfected properly may still transmit a pathogenic micro-organism. Sterilization, on the other hand, is the complete elimination of all micro-organisms including spores.
An steam sterilizer (autoclave) is a device that uses steam to sterilize equipment and other objects. This means that all bacteria, viruses, fungi, and spores are destroyed. Autoclaves work by allowing steam to enter and maintaining extremely high pressure for at least 15 minutes. Because damp heat is used, heat-labile products (such as some plastics) cannot be sterilized or they will melt.