Dirty Dishwashers Hold Potentially Fatal Germs


There have been many articles recently about dishwashers harbouring a number of potentially fatal germs such as fungal pathogens. Apparently, these machines have the perfect environment of a hot and moist atmosphere, combined with an alkaline water produced by the dishwasher tablets to allow these germs to flourish.

Several studies have looked at the threat of these pathogens and tested over 189 dishwashers in 101 homes throughout the world. The results showed that around 62% of these had a fungus growing in the rubber band on the door and more than half of these contained the black yeasts Exophiala dermatitidis and E. phaeomuriformis, which are known to be dangerous to human health.

These black fungi are of particular concern to people suffering from cystic fibrosis and asthma as they attack the lungs and are also known to colonise in the lungs of patients with cystic fibrosis. Biologist, Dr Polona Zalar, of the University of Ljubljana, Slovenia, who carried out the tests said “the potential hazard they represent should not be overlooked”.

And the problem does not only lie with the dishwasher itself. It appears that items removed from the machines were also covered in the black fungus including plates, dishes and cutlery.


The fungi seemed to somehow evolved into a super fungus that can withstand the extreme intermittent temperatures of between 60C to 80C degrees and the salt and detergent of a dishwashers normal cycle. In some cases, this black fungi or yeast has proved to be fatal to human health, in particular to those who have an existing chest complaint.

The study, which has been published in Fungal Biology, say the invasion of black yeasts into our homes is a serious potential health risk. So how can we minimise the risk of these fungi growing and spreading in our dishwashers? By taking these few simple hygienic steps you can easily stop any potential growth and make sure that your dishwasher is doing what it is supposed to do – clean your dishes thoroughly.

  • Always use the hottest setting on your dishwasher.
  • Clean the rubber band with a strong disinfectant designed to kill all germs.
  • Regularly clean the inside of your dishwasher with bleach.
  • Remove all food from the filter and clean thoroughly.
  • Keep a dishwasher cleaner inside the washer specifically designed to wash the inside.
  • Remove all bits of food before you place plates and dishes inside the machine.
  • At the end of a cycle leave the door open to air the washer.

Show Comments

No Responses Yet

    Leave a Reply

    This site uses Akismet to reduce spam. Learn how your comment data is processed.