As stated in the 2008 CDC Healthcare Infection Control Practices Advisory Committee Guideline for Sterilization and Disinfection in Healthcare Facilities, “... more than 30 years ago, Earle H. Spaulding devised a rational approach to disinfection and sterilization of patient-care items and equipment. This classification scheme is so clear and logical that it has been retained, refined and successfully used by infection control professionals and others when planning methods for disinfection or sterilization.”

The Spaulding classification scheme places reusable medical instruments or devices into three categories of ascending risk for infection. The lowest risk items are termed “non-critical” and include patient care equipment like blood pressure cuffs and wheelchairs. This equipment requires only cleaning and low-level disinfection and is generally not the responsibility of sterile processing staff. 

The next level of risk includes devices that contact mucous membranes (e.g., the gastrointestinal or genitourinary tracts) or non-intact skin. These non-sterile parts of the body can tolerate being exposed to low numbers of bacterial spores without developing an infection. Devices in this category are termed “semicritical” and include items such as bronchoscopes and endoscopes. Semicritical items require only high-level disinfection as the terminal reprocessing step. The primary intent of high-level disinfection is to eliminate pathogens from the prior patient to prevent transmission of infection-causing pathogens to another patient.

Instruments and devices that enter sterile body cavities or the vascular system comprise the third and highest level of risk for infection. These include surgical instruments, implants and devices used intraoperatively within the sterile field. These devices are categorized as “critical” and must be free of all microbial life, or sterile.