How to avoid unwanted microbes in cleaning products

The production of sufficient quantities of micro-organisms for a microbial cleaner is done by standard fermentation technology. Any fermentation process has the potential to result in unwanted micro-organisms present in addition to the desired microbes. Depending on the particular process conditions, these unwanted or contaminating microbes might include pathogens and/or might produce toxins. Moreover, they could also interfere with the intended microbial action. This is widely acknowledged (OECD, 2011), and operators of biotechnological processes have therefore established process controls and quality assurance systems aimed at both avoidance (too high levels) of and checking for contaminants.

Information from manufacturers indicated huge variations in process controls and quality assurance. In some cases, this raises doubts on hygiene, quality and consistency of the products. Such doubts are also reinforced by the findings of a study conducted by the Dutch Food and Consumer Product Safety Authority (VWA, 2004). The microbiological analysis of microbiological cleaning products identified huge variations in total viable counts, indicating problems with consistency and shelf life. They also found microbial contaminants including, in one case, a risk group 2 organism associated with human infections. These hygienic problems and the fact that some of the strains being used belong to microbial species known as either opportunistic pathogens or food contaminants, resulted in a VWA recommendation not to use microbial cleaner in areas of food processing and preparation and also not with particular risk groups (YOPI: young, old, pregnant, immune compromised). More recently, they also advised against the use in hospitals based on the same reasons (personal communication). Other applications, e.g. for sanitary purposes, are considered acceptable by the VWA.