Earle H Spaulding

Earle Spaulding of Temple University (Philadelphia, Pa) in a 1939 paper on disinfection of surgical instruments in a chemical solution proposed "a strategy for sterilization or disinfection of inanimate objects and surfaces based on the degree of risk involved in their use." for the medical community.

"Due to his extensive study of disinfection and sterilization of medical instruments, Spaulding further refined his classification of appropriate treatment of medical devices based upon how a device is used. Chemical disinfection was classified as low level, high level, and sterilization based upon whether a device contacted intact skin, mucous membranes, or was introduced into the sterile cavity of the body."

"A RATIONAL APPROACH TO DISINFECTION AND STERILIZATION - More than 30 years ago, Earle H. Spaulding devised a rational approach to disinfection and sterilization of patient-care items and equipment.14 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."

...
Wikipedia