Description
Cleaning and disinfection
15.1 Introduction
Cleaning and disinfection practices are an essential part of contamination control in the pharmaceutical industry, especially in relation to the microbiological control of cleanrooms. Disinfectants are also important for use in the microbiology laboratory.
An important step toward achieving microbial control within a cleanroom is the use of defined cleaning techniques, together with the application of detergents and disinfectants. The objective of cleaning and disinfection is to achieve appropriate microbiological cleanliness levels required and for an appropriate period of time [1]. This chapter examines both detergents (which “clean”) and disinfectants (which
remove or eliminate microorganisms). Detergents are cleaning agents and are deployed to remove “soil” from a surface. The removal of soil is an important step prior to the application of a disinfectant, for greater the degree of soiling remaining on a surface, then the lesser the effectiveness of disinfection. A disinfectant is a type of
chemical germicide that is capable of eliminating a population of vegetative micro organisms (although some disinfectants are sporicidal, a chemical does not need to be sporicidal to be classified as a disinfectant). A disinfectant that can kill spores is
sometimes described as a sterilant or chemosterilant [2]. Disinfectants, of varying formulations, have been used since the late nineteenth century [3].
Disinfectants vary in their effectiveness against different types of microorganisms, a variation relating to both the intrinsic resistance of different microorganisms and the range of different types and formulations of disinfectants. Furthermore, different
disinfectants act in different ways depending upon their active ingredients.
15.2 Cleaning
Cleaning is the process of removing residues and “soil” (such as dirt, grease, and protein residues) from surfaces to the extent that they are visually clean. This involves defined methods of application and often the use of a detergent. Importantly, the act of cleaning is necessary prior to the application of a disinfectant for a surface needs to be properly cleaned before the application of a disinfectant in order for the disinfectant to work ef-
ficiently [4], as disinfectants can either be inactivated by organic residues or the soil can create a barrier which prevents the disinfectant from reaching all of the microbial cells. While “cleaning” is not “disinfection”, the cleaning process can remove or dilute microbial populations. Furthermore, many detergents have chemical additives that can “disinfect.” However, a cleaning agent will not meet the criteria for disinfection required by the European and US standards for disinfectant validation in terms of reducing a microbial population of a defined range by the required log reduction.
Study of morphology, classification, reproduction/replication and cultivation of Fungi and Viruses. Classification and mode of action of disinfectants Factors influencing disinfection, antiseptics and their evaluation. For bacteriostatic and bactericidal actions. Evaluation of bactericidal & Bacteriostatic. Sterility testing of products (solids, liquids, ophthalmic and other sterile products) according to IP, BP and USP.
