Disinfection, sterilization, and antisepsis: An overview.

All invasive procedures involve contact by a medical device or surgical instrument with a patient's sterile tissue or mucous membranes. The level of disinfection or sterilization is dependent on the intended use of the object. Critical (items that contact sterile tissue, such as surgical instruments), semicritical (items that contact mucous membranes, such as endoscopes), and noncritical (devices that contact only intact skin, such as stethoscopes) items require sterilization, high-level disinfection, and low-level disinfection, respectively. Cleaning must always precede high-level disinfection and sterilization. Antiseptics are essential to infection prevention as part of a hand hygiene program, as well as other uses, such as surgical hand antisepsis and preoperative skin preparation.