University of Florida engineers have discovered that microwaving kitchen sponges and scrub pads for 2 minutes kills virtually all of the pathogenic organisms infesting them. Upon reading about this, I set out to do an experiment myself. From my experience, it does appear to work as long as the sponge or scrub pad is saturated with water. (Remember, metal cannot be placed in an operating microwave oven.) Simply cleaning these items in a dishwasher is not nearly as effective.

I remember when we first got a microwave oven about 30 years ago. It was a fascinating piece of equipment at the time, especially for a teenage guy who refused to read directions. None of seven children in the family had the slightest idea how to properly operate one, so personal experiments were inevitable. It is a small wonder that we did not use the microwave as a sterilizer on ourselves, let alone ‘nuke’ our food.

With each test, we learned something new. Eventually we learned how to cook potatoes without making them explode. An artificial indoor lightening storm proved that you do not want to put any kind of metal inside while cooking. An instant vaporization of water inside a mug was one of my personal accidents. The loud bang throughout the house was an important science lesson on the nature of super-heating H2O.

Most disturbing were the rumors abounding throughout the neighborhood about live animals placed inside one of these things! I certainly hope this was just gossip and nothing more. We interpreted them as bad attempts at humor. The thought of something like that actually happening is just pure horror!

Today cooking with a microwave oven is just an ordinary, everyday kind of thing to do. We often laugh at the stupidity we displayed in our youth concerning this important kitchen appliance. When I heard about these various objects (including contaminated syringes) being placed inside one for purposes of cleansing, I paid attention.

Home Application

The kitchen microwave is an appliance that more than 90% of all Americans have. Many even have more than one. This idea for a new barrier against food borne illness is a viable one. Most people can easily put this method of decontamination into practice.

Kitchen towels and sponges are the number one way that these pathogens are transmitted from one surface area to another. When they are left out for several days, these objects become cultures for all sorts of the toughest germs. If you zap these little buggers out of existence every other day at their primary source, then they have far less a chance at spreading to your prepared food.

The researchers went another step further to clarify the efficacy of this technique. They saturated their test sponges and scrubbing pads with raw sewage. They used some as a control group while ‘nuking’ the others with an ordinary off the shelve microwave oven. Then they compared the two sets. More information about the results of this experiment can be found at LaboratoryTalk.

Even with raw sewage, 99% of all pathogens were eliminated within 2 minutes. The only ones surviving were a few Bacillus cereus spores. Even they were destroyed after 4 minutes! If it can do that, then this sterilization method can easily handle any germ that could grow in your sponge.