You wouldn’t think that the sponge sitting in your kitchen sink could make you sick—but it can. The whole purpose of a sponge is to soak things up, and that includes soaking up bacteria.
Past claims that you can disinfect these handheld scrubbers have been proven false. So if you have a sponge lurking in your kitchen, you probably want to get rid of it.
Your microwave won’t save you.
Sponges are a cheap and convenient product for household cleaning. There’s no inherent issue when using them, but over time, you might develop a problem. Some websites will say you can kill a sponge’s bacteria by tossing it in a dishwasher or zapping it in a microwave. Science disagrees.
A study conducted by Markus Egert and researchers of Furtwangen University in Germany found that household sponges are definitely grosser than we think. The researchers took sponges from 14 different homes, collected samples from the top and bottom of each one, then used genetic sequencing to determine what type of microbes could be found in the cracks and crevices we rub on our dishes.
A Motherload of Bacteria
According to the research, “A total of … 9 phyla, 17 classes, 35 orders, 73 families and 118 genera” of bacteria were discovered on the sponges.
In layman’s terms: That’s a lot of microorganisms. A particularly nasty bacterium called Moraxellacea was there in force. That’s a bug that’s commonly found on human skin, and it’s responsible for making your dirty laundry smell. That’s gross, but it probably won’t make you sick. But the researchers found other strains that were closely related to disease-causing microbes.
A few of the volunteers said they did regularly clean their sponges, but research found this made no difference in the bacteria population. However, the “cleaner” sponges did contain more of the bacteria linked to diseases. So when you pull that sponge out of the microwave, you’re potentially risking your health more than if you had left it alone.
Cleaning vs. Disinfecting
The sponge may be a lost cause, but you can at least be sure the rest of your kitchen isn’t teeming with germs. This sounds simple, but first you need to know the difference between cleaning and disinfection.
Cleaning involves wiping up grease, food residue, or any other visible spills. Although cleaning makes a kitchen look nice, it also basically just smears bacteria from surface to surface. Disinfecting kills bacteria, viruses, or parasites that could be lurking on the surfaces of your home.
What can you do?
First and foremost, change sponges regularly.
“From a long-term perspective, sponge sanitation methods appear not sufficient to effectively reduce the bacterial load in kitchen sponges and might even increase the shares of [disease-linked] bacteria. We therefore rather suggest a regular (and easily affordable) replacement of kitchen sponges, for example, on a weekly basis,” wrote Egert.
The way you wash and dry kitchen items can also help reduce bacteria growth. It’s a good idea to keep strong disinfectant cleaners, like bleach, around the house to use frequently when cleaning.
The EPA offers a list of registered disinfectants if you’re wondering what products to use. Oh, and if you’re worried about chemical residue in your home, vinegar and baking soda kill certain types of microbes—just not as effectively as bleach.