Get Rid of Smelly Sponges

By Nicole Irving, Publisher and Editor-In-Chief

In one week, I can smell it.

A foul, musty, stinky stench lurking in the kitchen. Soon, I smell it on my hands and around the sink as I do the pile of dishes from the night before. Is it the garbage disposal? The dog under my feet?

Nope, it’s the sponge. The very tool I am using to clean the cutlery—gag.

Why do sponges smell?

According to research published in, the very sponge I used to clean the dirty dishes also harbors zillions of microbes, many of which are the same kinds of bacteria that can cause pneumonia and meningitis. One of the main culprits is Moraxella osloensis, a microbe that “can cause infections in people with a weak immune system and is also known for making laundry stink, possibly explaining your sponge’s funky odor.”

So, how do these cleaning vessels gather so many bacteria? One reason is that sponges used daily never really dry out, allowing bacteria and other viruses to grow in the damp atmosphere, according to a CNN report. In addition, sponges also collect food particles that seep into the damp sponge, allowing for bacteria to grow.

A 2017 study by Scientific Reports found that there were 362 kinds of bacteria found on sponges. According to the research, kitchen sponges are likely to collect and spread bacteria from kitchen surfaces, whereby they could make

their way into the human body through contaminated hands or food.

How to clean sponges?

According to Healthline, the reason microwaves are used to clean dirty spongeis “because radio-frequency waves in
a microwave cause thermal (heat) and nonthermal (non-heat) effects, causing the water molecules inside a cell to vibrate. The
friction associated with this vibration causes increasing levels of heat, which kills the bacteria.” A 2007 report by the Agricultural Research Service, part of the U.S. Department of Agriculture found that “microwaving sponges killed 99.99999% of bacteria present on them, while dishwashing killed 99.9998% of bacteria.”

There are also a handful of helpful DIY methods to get the gunk out of your sponges. For example, Good Housekeeping recommends an at-home recipe that entails mixing 3⁄4 cup of bleach with one gallon of water, then soaking sponges for 5 minutes to kill 99.99% of germs and bacteria on the sponges.

Although these cleaning practices can help, nothing is as effective of ridding your sponges of odor than replacing them entirely. The 2017 report by Scientific Reports study found that regularly sanitized sponges did not contain less bacteria than the dirty ones. Data showed that some sponges, even when cleaned, showed an increase in the abundance of Moraxella, which caused them to smell even more pungent. Meaning, that the only true way to get rid of the harmful bacteria and that awful smell, is to throw them away.

What can live on a sponge?

According to Health Line, hundreds of bacteria can live on a sponge, including the following:

  • E. coli may give you an upset stomach and/or diarrhea.
  • Enterobacter cloacae can cause skin and abdominal infections, among other illnesses.
  • Klebsiella oxytoca can cause vaginal infections, like a UTI.
  • Mycobacterium avium can cause pulmonary-related diseases in people with weakened immune systems
  • Staphylococcus aureus can cause a staph infectionthat results in fever, swelling, andirritated skin.
  • Salmonella can cause food poisoning.

So, what do we do?

  1. After use, ring sponges out completely, to allow them to dry out.
  2. Wipe down counters and the house with disposable wipes or paper towels, as to not spread bacteria/germs on any other surface.
  3. Replace sponges every week, or as soon as they begin to smell.
  4. Nix the sponges all together and use silicone brushes to clean dishes.

Related Articles: