Germophobia story of the week: SpongeBath sponge cleaner system

Oh my.  This story is littlered with so much over the top germophobia I do not know where to begin: The Dirt on Your Sponge –  The story, by Penelope Green, discusses how Tod Maitland and Matthew Flannery have developed a sponge cleaning system called “SpongeBath”.  This is going on sale on Amazon and Bed Bath and Beyond in September.  Why is it needed?  Well, they assert

“that your kitchen sponge, a smelly, disgusting bacteria magnet, is 200,000 times dirtier than your toilet seat. (This interview has been condensed and edited.)”

That is a perfect quote for David Coil who wrote that he would “rather lick a toilet seat than a cellphone“.  In writing this he was basically trying to point out that there are microbes everywhere and that toilet seats are not the germiest places in the world (they are actually cleaned more often than many other sites).  So – it is not really that big a deal if a sponge has more bacteria than a toilet seat.  What matters perhaps more is what kind of bacteria are there.

So anyway – these two ended up being grossed out by sponges and developed a system to soak sponges in a cleaning solution made of “Citric acid and silver.”.  This to me seems like a potentially bad idea since I am not sure what the long term effects of such a soak are.  They justify this mix because “Both of those have been around for thousands of years.”  How does that make using them wise????

In response to question about how they knew sponges were dirtier than toilet seats they say “The Wall Street Journal. But I’m sure they got it from someone else. There’s a lot out there about how horrible your sponge is.”  So – alas they are reading the germophobia literature not the rationale stuff.  Sure – sponges probably are in fact gross much of the time and one should probably worry about what is in them.  But this seems a bit over the top as a response.

The developers try to make the connection between cleaning sponges and foodborne illness “You can’t directly track it to the sponge, but food-borne illnesses cause over 3,000 deaths every year.” and “There are 48 million cases reported every year. The sponge is the No. 1 cross-contaminator.”.  Hmm.  I am not aware of these numbers coming from the literature.  I am aware of studies showing that sponges are indeed a risk factor (e.g., see this web site). So I am not trying to discount the possible risks from sponges.  But I would very much like to see more on the effects of soaking sponges in silver and citric acid before such products get widespread use.  Seems like this could potentially lead to various forms of resistance and also could leave a blank slate that might allow nasty microbes to grow better on the sponge than if one was not so enthusiastic about sterilization.


4 thoughts on “Germophobia story of the week: SpongeBath sponge cleaner system

  1. How would you suggest we get past this trend of germophobia we see so often in media and the general public? It seems like so many people have been imbibed with this aversion to “germs” that it’s almost impossible to convince them of anything BUT sterilizing every possible surface.

    1. Well, if it is really a phobia (as it is in some people) that is probably best dealt with by medical professionals. But for all the others who just hate germs or are freaked out by them, I think there are many options.

      1. Describe the risks that could come from killing everything.

      2. More emphasis on possible good things microbes do. Certainly there are lots of people going crazy on fermented foods and such and they clearly are not germophobic.

      3. Make it more difficult to kill all the microbes. Such as by outlawing use of triclosan in buildings.

      1. I actually just found out that there is Microban on the inside lining of my lunchbox. I didn’t think much of it at the time, since I was only looking at the utility of the lunchbox and it happened to have an anti-microbial coating on the inside, but now I’m starting to consider ditching it for something without that lining.

  2. It seems to me that the views people have on germs break down into three groups: 1. germophobia, 2. germs are good, more are better, so please don’t kill any and please eat more of them (yogurt, probiotics, etc.), and 3. I dunno, but aren’t the government scientists taking care of all that?

    Are the answers to any important questions that simple?

    How many people do get sick from or die of foodborne illness each year? JE wrote in the original post: “Hmm. I am not aware of these numbers coming from the literature.”

    Interested in seeing where the numbers might have come from, I Googled “How many foodborne illnesses per year” and got this as the first result:

    “CDC estimates that each year roughly 1 in 6 Americans (or 48 million people) gets sick, 128,000 are hospitalized, and 3,000 die of foodborne diseases.”

    Not from the literature and only an estimate. CDC does provide a description of their methodology at But it seems like a likely source for the “germophobic story [authors] of the week.

    I don’t know if that is “literature,” but having been involved in past CDC public releases and in some “review and editorial decisions on “literature,” I believe that there is more (and possibly higher quality) review than for many studies published in a lot of peer-reviewed journals.

    I looked at the link JE provided to the article on sponges and was not overly impressed. So I looked a little more deeply and I found the following article from the journal Food Control: Effective household disinfection methods of kitchen sponges by Sharma et al, 2009. Food Control 20 (2009) 310–313.

    a b s t r a c t
    “Several household disinfecting treatments to reduce bacteria, yeasts and molds on kitchen sponges were evaluated. Sponges were soaked in 10% bleach solution for 3 min, lemon juice (pH 2.9) for 1 min, or deionized water for 1 min, placed in a microwave oven for 1 min at full power, or placed in a dishwasher for full wash and drying cycles, or left untreated (control). Microwaving and dishwashing treatments significantly lowered (P < 0.05) aerobic bacterial counts (<0.4 log and 1.6 log CFU/sponge, respectively) more than any chemical treatment or control (7.5 CFU/sponge). Counts of yeasts and molds recovered from sponges receiving microwave (<0.4 log CFU/sponge) or dishwashing (0.4 log CFU/sponge) treatments were significantly lower than those recovered from sponges immersed in chemical treatments. Our study shows that microwaving and dishwashing treatments may kill foodborne pathogens in a household kitchen environment."
    The article (presumably qualifying as "literature") starts out "Cross contamination of foodborne pathogens in the household kitchen may contribute to the estimated 76,000,000 cases of foodborne
    illness in the US, each year (Mead et al., 1999)." The full reference is Mead, P. S., Slutsker, L., Dietz, V., McCaig, L. F., Bresee, J. S., Shapiro, C., et al. (1999). Food-related illness and death in the United States. Emerging Infectious Diseases, 5, 607–625.

    Does that make the numbers right? I don't know. Does it matter? I don't know.

    Sponges are a source associated with foodborne disease. That seems not to be in dispute in either the citation in the original post, or the citation to a study (clearly part of the "literature"). The numbers are considerably higher than the CDC number and that in the excessively germophobic article that incited the original post in this thread. They were from an article submitted in 2008 as compared with the CDC's numbers developed in 2011. Maybe we are making too much fuss about numbers when we don't really know which microbes are good for us, which are bad for us, which are necessary for the ones that are good for us, and which are good or bad for the ones that are necessary for the ones that are good or bad for us. We are talking about communities and don't know the answers to some fundamental questions. Asking about one organism at a time might not get the answers we need. I don't know, but it seems to me that the communities and their hospitable and inhospitable environments all need to be studied as a system.

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Jonathan Eisen

I am an evolutionary biologist and a Professor at U. C. Davis. My lab is in the UC Davis Genome Center and I hold appointments in the Department of Medical Microbiology and Immunology in the School of Medicine and the Department of Evolution and Ecology in the College of Biological Sciences. My research focuses on the origin of novelty (how new processes and functions originate). To study this I focus on sequencing and analyzing genomes of organisms, especially microbes and using phylogenomic analysis (see my lab site here which has more information on lab activities).  In addition to research, I am heavily involved in the Open Access publishing and Open Science movements.