A washing machine is simply practical: It easily removes dirt, bacteria and germs from the laundry at a wide range of temperatures. But especially with 60° or 95° wash loads, germs can spread in the washing machine.
A research team from Furtwangen University, Gießen University and Henkel AG & Co. KGaA (Düsseldorf) conducted a small study to examine bacteria in household washing machines.
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The study: the process
50 samples from 13 household washing machines were examined. The washing-up compartment, the porthole seal, the pump sump tank and laundry fibers from a test wash were checked for bacteria and germs. In addition, the machine owners provided information on washing behavior. The scientists were thus able to pursue the questions of where bacteria cavort and which factors and influences control their composition.
The main sources of germs are the washing-in chamber and the seal
The bacterium “Moraxella osolensis” was found most frequently. It settles on the porthole seal and causes bad smells. The highest diversity of bacteria, on the other hand, was in the washing-up compartment. The researchers explain this diversity due to the high washing temperature, even if this may sound paradoxical at first. The hot water also heats other areas of the washing machine and promotes the growth of bacteria there. However, it still needs to be clarified which factors have the greatest influence on bacterial growth, such as how often washing is carried out at high or low temperatures.
The researchers found a total of around 229 types of bacteria , some of which were classified as pathogenic. However, this risk would only exist for people with a weakened immune system . In order to avoid this, bad odors and mold , the washing machine should be cleaned regularly and the washing-up compartment cleaned !
