While many of us carefully consider which soaps, powders, or sprays we use to clean our homes, we rarely think twice about the tools we use them on or with. One particular item common to most homes (and rightfully so) is the beloved sponge, which we use to clean dishes, wipe down counters, and scrub sinks, tubs, and tiles. But recent studies have confirmed that these versatile little items are microbial hot spots that harbour a multitude of bacteria.
Our homes and other indoor environments are considered BE (built environments), and in industrialized countries, we spend up to 90% of our lifetime within them. Yet BEs harbour “a huge variety of microhabitats that are colonized by a wealth of microbial species.” and, shockingly, it has been shown that kitchen environments are dirtier than toilets.
The researchers of the study, which was published in Scientific Reports, conducted a genetic analysis of bacteria on 28 samples from 14 used sponges and found that 5 of the 10 most common bacterial groups had pathogenic potential, including Acinetobacter johnsonii, Chryseobacterium hominis, and Moraxella osloensis. This study is the most comprehensive analysis yet of the microbiome (the community of bacteria) living on kitchen sponges. The also examined unused, newly purchased sponges and found them to be bacteria-free, which is why they suggest using a new sponge every week.
NPR spoke to one of the microbiologists who led the study, Markus Egert, who says “there’s hardly any habitat on Earth where you’ll find similar densities of bacteria, except for the human intestinal tract.”
The study suggests that you can wet the sponge a bit and nuke it if you want to clean it, but that’s not an option for those of us who know about the dangers of microwaves and accordingly don’t keep them in our homes. But even if you choose to microwave it or boil it, you’ll still only reduce about 60% of the bacteria, so they won’t be entirely sterile.
Dos & Don’ts of Sponges
Replace Frequently. As the researchers suggested, it’s best you change your sponge weekly to avoid the risk of food poisoning, among other things. If your sponge develops an odour or begins to fall apart, that’s a clear sign that its useful days are long gone and it’s time for a new one.
Store in a Dry Location. Right after using your sponge, be sure to wring it dry and clear it of any food before putting it away in a dry location — not under the sink or in a closed container. If you leave it wet on the sink or countertop, it’ll take longer to dry, giving bacteria more time and opportunity to grow.
Clean First. This may sound like a weird one, but before using your sponge to clean off all the food from your dishes, clean it with your hand first. This will help your sponge to last a little longer.
Wipe Up Meat Juices. When a spill occurs in the home, especially from beef or poultry, do not use your sponge, as this increases your chances of spreading harmful food borne pathogens. It’s far safer to use paper towel.
Cross Contaminate. Essentially, when you use one sponge for multiple tasks, you’re just building up the bacteria. If you clean dirty dishes or (please, no!) the toilet and then wipe your countertops, you are spreading those millions of germs onto all your surfaces, making it much more likely you’ll get sick.
Use Dishcloths. Again, stick to using a sponge for one thing and a dishcloth (if you choose to use it) for a separate purpose. Dishcloths can still carry enough bacteria to get you sick, so when you do choose to wash them, be sure to do so in hot water.
Realistically, sponges aren’t the safest or most sustainable choice when it comes to cleaning your dishes or your home, so I spent some time scouring the internet (excuse the pun) and found a pretty fantastic list of eco-friendly cleaning tools, compiled by The Spruce, that are definitely worth trying:
- Campeon 6-Inch Natural Corn Quality Escobeta De Raiz Tan
- Loofah-Art Natural Loofah Scrubbers
- Natural Value Walnut Scrubber Sponge
- Safix Scrub Pad
- Scotch-Brite Greener Clean Scrub Sponge
- Twist Ravioli Hemp Scrubby
If you know of any other sponge alternatives or safer ways to sanitize and clean a used sponge, let us know!
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