Your Sponge is the Grossest Thing in Your Kitchen 

Liz Biscevic—New and Improved

There’s no way around it: sponges are disgusting. These soggy, sink-side cesspools teem with nasty bacteria, just waiting to attack any compromised immune system that crosses their path. Sponges are a near-ideal breeding ground for bacteria—porous, warm, wet, and consistently fertilized by the stuff we clean. You might think your dish soap is killing the germs from your food and utensils, but that just isn’t the case. In a 2016 study, scientists ran a “microbiome analysis and confocal microscopy of used kitchen sponges” and revealed a “massive colonization” of potentially illness-causing bacteria.

“Despite common misconception, it was demonstrated that kitchen environments host more microbes than toilets,” wrote the study’s authors in its introduction. “This was mainly due to the contribution of kitchen sponges, which were proven to represent the biggest reservoirs of active bacteria in the whole house.” Even among “antibacterial” sponges, the scientists still found a whole menagerie of microbial menace. The foamy implements were home to Acinetobacter, the greatest cause of human disease, and a cause of meningitis, pneumonia, and UTIs; Chryseobacterium, which can sometimes lead to cystitis or peritonitis; and Moraxella, a source of ear and sinus infections, and the reason for the nasty smell your sponge takes on after a few weeks.

But because they’re used for cleaning, many people will never even think to question the relative repulsiveness of their sponge, blissfully unaware that they’re scrubbing off last night’s lasagna with raw chicken germs.

Sponges were invented in 1937 by a German scientist who accidentally discovered polyurethane foam, the polymer that constitutes most of these cleaning pads. Since then, the sponge industry hasn’t exactly been a hotbed of innovation, and in most cases, the materials and process used to create them remain essentially the same as in the ‘30s.

Not only is one of those primary materials derived from fossil fuel, but when sponges are thrown in the trash, they can take up to 52,000 years to biodegrade in landfills. In an attempt to kill at least some microbes, the supposedly antibacterial sponges most of us use today also come loaded with toxic chemicals like the pesticide triclosan, which is believed to destroy aquatic ecosystems, especially algae and coral. In humans, triclosan has been linked to cancer, developmental problems, and skin irritation. It’s worth noting that the FDA recently banned Triclosan from being used in antibacterial soaps and body wash because it poses too many health risks, including an increased risk for heart disease and impaired muscle function.

So, what can the average dishwashing consumer do about the unappealing aspects of kitchen sponges? At least on the hygiene side, there’s been some controversy recently. It is popularly believed that you can completely disinfect a sponge by microwaving it, or washing it in the dishwasher, or soaking it in vinegar. But according to the 2016 study, there was actually more bacteria found on sponges that had been routinely “disinfected” via the microwave, or hot, soapy water. (Although for this part of the study only a handful of frequently cleaned sponges were tested.) Despite the 2016 study, the USDA still claims dishwashing (with a heated dry cycle) or microwaving (for a minute) a damp sponge can kill 99 percent of bacteria. This conflict could perhaps be attributed to the differences in disinfecting sponges in a home or laboratory environment. Most experts agree that with either method, some bacteria will still survive, and that sponges shouldn’t be used to clean items that have come into contact with raw meat. Even with regular sponge cleanings, they should be tossed out every week or two, which is a lot of waste to add to the environment.

In an interview with Business Insider, microbiologist and pathologist Philip Tierno said there’s only one way to really clean a sponge: throw it in a simple solution of ¾ cup bleach and one gallon of water. But bleach is its own environmental can of worms and is also terrible for your skin.

While the jury’s still out as to why we don’t already have a more hygienic way to scrub our dishes, there are some niche companies and green brands out there offering more environmentally friendly alternatives. Pure cellulose sponges, for example, are made from 100 percent organic and biodegradable materials. Because they aren’t made with petroleum byproducts and don’t contain antibacterial additives, they are more eco-friendly than traditional sponges.

Yet green sponges also don’t contain any adhesives and tend to trap residue and particles inside, which can cause them to fall apart or quickly start to smell. I recently tried out an eco-friendly, all-natural cellulose sponge from my local co-op, but after only a week of use, it crumbled, sent to a dishwatery grave by the scrubbing gauntlet of pasta night.

On Etsy, too, there seems to be a wide selection of handmade, eco-friendly sponges that are able to be washed, dried and reused. They’re a bit pricey, though, and would still need to be disposed of pretty often to prevent a buildup of bacteria.

For the frugal eco-warrior, consider rags, which can be made out of old clothes. You can boil them after each use to sterilize, and then toss them in the wash with the rest of your laundry. Or you can add white vinegar to your laundry machine and wash on hot.

It’s also important to remember that nothing in our homes is completely germ-free—our phones for example, carry 10 times more bacteria than a toilet seat, and we put those things on our faces. That may actually be a good thing, for instance, we’re learning more and more about “good” bacteria that strengthens our immune systems. Yet there’s probably some middle ground between constantly sterilizing everything around us and breeding bacteria like some kind of low-maintenance pet.

Sure, future generations—whose dishes will be probably be destroyed and reformed on a molecular level after each use—will laugh at us sponge-wielding, germ-farming slobs in hindsight either way. But until we have a revolution in sponge technology and design, for goodness sake, always remember to wash your hands after using any kind of sponge.