Sterilization is the process by which an article, object or surface is freed of all microorganisms in the vegetative form and in the spore state. This includes viruses, bacteria, their spores and fungi. This term is distinguished from disinfection in which liquid chemicals are used to destroy all pathogenic organisms capable of giving rise to infection on inanimate surfaces. It is distinguished from antisepsis in which liquid chemicals are used to destroy pathogenic bacteria on animate surfaces such as skin. Finally, it is distinguished from sanitization in which a good cleaving process or boiling water is used to destroy bacteria. Sterilization assurance not only protects patients from cross infections, but also protects personnel from the infection of previous patients as well. Sterilization destroys all (100%) microbial forms such as bacteria, viruses, and spores to prevent cross-contamination to other patients and/or health care providers. Used items and instruments are commonly sterilized by a method known as autoclaving. Autoclaving is an excellent method of instrument sterilization using superheated steam (121 °C) under pressure. An alternative method for sterilizing instruments is dry heat sterilization. The advantage is that certain instruments which are vulnerable to corrosion with autoclaving can be dry heat sterilized. The disadvantage of dry heat sterilization is that it takes more time and requires higher temperatures than autoclaving.