ABSTRACT
The evaluation of chemical germicides predates the golden age of microbiology. The microbicidal effects of various chemicals have been investigated ever since microorganisms were first discovered. However, it was not until the late 1800s and early 1900s that any attempt was made to standardize these types of evaluations. The works of Koch [1], Rideal and Walker [2], Chick and Martin [3], and others formed the foundation of modern disinfectant test methodology. Current procedures can be classified into at least two main categories, based on their fundamental design: those that provide information on the antimicrobial activity of the product, and those that attempt to simulate real-life practical uses of the agent. Methods in this first category, sometimes referred to as in vitro tests, are usually
2 Cole and Robison
suspension tests in which all test parameters are strictly controlled. These provide reliable information on the relative efficacy of a test agent. Methods in the second category, sometimes called practical tests, include carrier methods, capacity tests, and surface techniques that simulate actual disinfection protocols. These represent an evaluation of the specific disinfection procedure as much as they do the efficacy of a particular agent in use.
