Earle Spaulding of Temple University (Philadelphia, Pennsylvania) 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".^[1] In order to simplify the nature of the disinfection process, Spaulding classified instruments and items used in patient care according to infection risk into "critical", "semicritical", and "noncritical" categories.^[2] He also classified levels of germicidal activity as "high", "intermediate", and "low". While influential, the Spaulding scheme is susceptible to oversimplification and can be difficult to implement.^[2]