Hygienic quality of cleaning cloths used in professional cleaning of private domestic homes

The objective of this laboratory study was to obtain general background information concerning professional cleaning in private domestic homes. The specific aim was to examine the effect of storage and washing of dirty cloths on their hygienic status. The effect of storage on the number of Staphylococcus aureus bacteria in cleaning cloths was examined using current or potential materials for professional cleaning in private homes. The bacterial content increased in microfibre cloths in some cases during a normal working day (8 h storage), and more clearly after 16 h or 48 h of storage. Disposable fibre cloths did not promote the growth of microbes as well as microfibre cloths. The effect of detergents on the hygienic status of cleaning cloths was unclear: some cleaning agents appeared to enhance the growth of bacteria, while others did not. In many cases, organic substances, i.e. protein added to the cloths, enhanced the growth of microbes. Washing of microfibre cloths at 60°C reduced the numbers of bacteria on the cloths but did not remove them entirely. Storage of dirty cloths before washing will probably cause difficulties in the proper washing of the cloths, and thus negatively affect their capacity for hygienic results in cleaning surfaces, as well as presenting a risk to the safety of the worker. Cleaning cloths should be washed as soon as possible after use: washing after each working day, at the latest, is recommended. Furthermore, cleaning cloths should be selected for professional use to allow washing at hot temperatures. The findings of this study could be used for training in professional home cleaning. They also provide valuable information for other branches of cleaning, including consumer use in households.