Cleaning together with disinfection is of great importance within pharmaceutical and healthcare products facilities in order to minimise contamination presence in cleanrooms. Contamination consists of debris, soiling and microorganisms. Conceptually, cleaning and disinfection are two distinct, although interlinked, processes. Cleaning is an important preparatory activity that is always required prior to disinfection, in order to remove any soil or residues that carry the potential to inhibit the effectiveness of the disinfection process to reach, make contact with, and kill microorganisms (1).
Cleaning is the process of removing residues and ‘soil’ (such as dirt, grease, protein residues and so on) 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 efficiently, 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. When applying a detergent (or disinfectant) to the target surface, the approaches are either without mechanical action (such as simply directly spraying) and with mechanical action (spray and wiping or soaking and wiping) (2).
Whilst "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 United States standards for disinfectant validation in terms of reducing a microbial population of a defined range by the required log reduction.
This paper looks at the importance of cleaning, application methods, and the role cleaning should play in validating the cleaning and disinfection process.