New Research: Cleaning Sponges is a Bad Thing

~ Contributed by J. Martin Little, MS, REHS, EHS IV

Recently, a study conducted by the University of Furtwangen (located in Germany) found that cleaning dirty sponges actually helps out the very worst bacteria, instead of destroying them.  A common method that people use to kill bacteria, ‘nuking the sponge’ in the microwave, only kills the weak ones while the strongest, smelliest– and even potentially pathogenic– bacteria will survive.

The destruction of the weak bacteria creates a space for the stronger bacteria to occupy and thrive due to a lack of competing microorganisms.  This cleaning method results in a sponge that actually becomes ‘stinkier and nastier’ and you may regret not just tossing it, as the report published in Scientific Reports states.

The study looked at the DNA and RNA of organisms from 14 different samples taken from sponges, and from those, 362 distinct species of bacteria where identified.  More interestingly, about 82 billion bacteria were living in just a cubic inch of sponge. “That’s about the same density of bacteria you can find in human stool samples”, the lead microbiologist, Markus Egert stated.  That’s right, it’s like you’re cleaning with a stool specimen.  This description may lead to an undesirable visual image; however,  it stresses the importance of maintaining clean, sanitized and well maintained cleaning devices in YOUR kitchen—whether it’s a home kitchen or a food service kitchen.  Remember that, according to our Rules and Regulations for Food Service Chapter 511-6-1-.05(1), Sponges may not be used in contact with cleaned and sanitized or in-use food-contact surfaces.

(Study content taken from the August 8th, 2017, New York Times)