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10 Fascinating Kitchen Sponge Facts and Statistics

Let’s bust some myths and highlight the truths about kitchen sponges.

Did you know that your kitchen sponge is the dirtiest part of the home, with possibly up to 10 billion bacteria colonies per square centimeter (1)? If this disgusting fact intrigues you, you’ve come to the right place.

We’re here to share shocking kitchen sponge facts and statistics. Not only will they have you running for another cleaning tool — it’ll give you more knowledge for your next trivia night!

Here are 10 kitchen sponge facts, plus tips for how to have a cleaner, less bacteria-infested home.

Top 10 Kitchen Sponge Facts and Statistics

  1. The kitchen sponge is dense with over 362 different species of bacteria.
  2. You should replace your kitchen sponge every two weeks.
  3. People used to use sea sponges to clean their homes.
  4. Otto Bayer invented the foam kitchen sponge by accident in 1937.
  5. Antibacterial sponges have a toxic chemical called Triclosan in them.
  6. A kitchen sponge is dirtier than a toilet.
  7. There are more hygienic sponge alternatives, such as cellulose sponges, silicone sponges, and dishcloths.
  8. Sponges are so dirty due to bacteria feeding on food residue.
  9. You should clean your sponge every few days, but it won’t significantly affect the number of bacteria.
  10. Sponge sales in the United States accounted for nearly five hundred million dollars in 2020.

Interesting Facts About Sponges

The kitchen sponge is a germ zone. We know that for sure. But there are more fun facts to be discovered about this standard cleaning tool — let’s dive in.

It Hosts 362 Different Species of Bacteria

Not only are there bacteria all over the sponge, but there are hundreds of different species. The kitchen sponge is dense with germs.

There are lots of little critters living inside your kitchen sponge. In fact, there aren’t many other places on Earth where you’ll find nearly as many bacteria in one space.

Your Sponge Needs Replacing

We’re not saying don’t use a kitchen sponge — you still can. But make sure you clean it every few days.

To clean it, you can dampen it and pop it in the microwave for a minute.

You should also replace it every couple of weeks. Unfortunately, that means it’s not the most eco-friendly cleaning product on the market.

Ocean Sponges Can Clean

Have you ever wondered where the term sponge comes from? Well, it actually comes from ocean sponges! With their coarse texture, these aquatic animals have been used as a cleaning tool for centuries.

Nowadays, we don’t typically use sea sponges for cleaning. Instead, kitchen sponges are made from synthetic materials like polyester or vegetal cellulose.

Who Invented the Sponge?

The common kitchen sponge was invented by a German scientist named Otto Bayer. In 1937, he accidentally invented the material used for kitchen sponges.

He was testing out different ways to use polyurethane foam when he made some that had too many air bubbles. It turned out to be great at washing dishes, and over time, the idea was perfected into what we use today.

Antibacterial Sponges are Toxic

If you’ve been tempted by a sponge marketed as antibacterial, think again. These sponges have been treated with a toxic chemical called Triclosan, a pesticide (2). This pesticide has links to cancer, a decrease in thyroid hormones, and skin irritation.

While you’ll probably not be harmed by washing dishes with gloves, you must remember that this sponge is touching your utensils.

A Kitchen Sponge Is Dirtier Than the Toilet

It’s true — your kitchen sponge hosts more bacteria than your toilet (3). It even contains harmful pathogenic bacteria, including E. coli and salmonella.

Don’t Clean Raw Meat

If you want to lessen the bacteria load on your sponge, make sure never to use it for cleaning raw meat off your dishes.

There Are More Hygienic Sponge Alternatives

Now that you realize how unhygienic a sponge is, you’re probably wondering: what should I use instead?

If you want to stick to the kitchen sponge, we recommend a cellulose kitchen sponge, like these Arcliber Sponges. These biodegradable sponges are made from wood pulp. Therefore, when you need to replace it every few weeks, it isn’t contributing to landfills.

Another great option is a silicone sponge, such as Geloo Silicone Dish Sponges. These are dishwasher safe, so you can deep clean them between uses. This also means you don’t need to throw them out or replace them as often.

You could also opt for reusable dishcloths like these Swedish Dishcloths. You can wash them in the washing machine, which keeps them fresh and clean.

If it helps, we haven’t used a kitchen sponge in over six years — and our dishes are sparkling clean!

What Makes a Sponge So Dirty

If you’re wondering why a sponge accumulates so much bacteria, it’s simply because it’s used to clean food. Food residue can feed bacteria, causing them to multiply. While you wash that bacteria off your plates and forks, it harbors on the kitchen sponge and hides in the pores, proving unsanitary.

It Doesn’t Matter How Often You Clean the Sponge

While we recommend cleaning your sponge in the microwave every few days, this will only slightly minimize bacteria (4). Studies have found that there is barely a difference between a regularly-cleaned sponge and a sponge that’s never cleaned.

So while you may want to try boiling or steaming the sponge, replacing it every few weeks is best.

Sponges Bring in Millions of Dollars

In 2020, the sponge and scouring pad market brought in sales of 478.57 million dollars (5). The five leading sponge companies are 3M co., Armaldy Brands Inc., and Corazzi Fibre Srl. Sponge sales are rapidly increasing since ordering them online is so easy.

Kitchen Sponge Bacteria Experiments

Numerous studies have discovered crazy amounts of bacteria on sponges. We’ll walk you through some of these scientific studies and what tests they did to find their results.

One study is: Microbiome analysis and confocal microscopy of used kitchen sponges reveal massive colonization by Acinetobacter, Moraxella, and Chryseobacterium species (6). In this study, experts analyzed kitchen sponges’ bacterial microbiomes through DNA sequencing, fluorescence, and laser scanning microscopy.

Another study is the Microbiological quality of kitchen sponges used in university student dormitories (7). Researchers analyzed 50 sponges from students at the University of Sharjah. They stored the sponges at room temperature for three to 10 days before assessing them. The results weren’t surprising: the sponges were dense with pathogenic bacteria.

One more we’ll look at: Evidence of Cronobacter sakazakii and Extended Spectrum Beta Lactamase (ESBL) producing bacteria (8). This study investigated microbial communities on 100 used kitchen sponges. They processed the sponges for various germs, including yeast, mold, micrococci, Enterobacteriaceae, and more. They found the sponges to be highly contaminated with various germs, including food-borne pathogens.

The conclusion remains the same: kitchen sponges are gross.


Who Invented Sponges?

Otto Bayer, a German scientist, invented the synthetic sponge by accident in 1937. Before him, people did use natural sea sponges to clean their homes.

What are Cleaning Sponges Made Of?

There are various materials used to make sponges. Most commonly, sponges are made from synthetic foam. But let’s look at the most common material types in detail:

  • Cellulose: This is a biodegradable option. It’s made from wood pulp, making it a more eco-friendly option, especially since you should still replace it every week or two.
  • Microfiber: Microfiber sponges are soft but aren’t as effective on food. Instead, they’re good for windows or vehicles.
  • Dobie sponges: These sponges are non-abrasive. They’re made from polyurethane with a nylon coating, making them great for cleaning more delicate surfaces.
  • Silicone: While these aren’t super popular yet, they are made with soft silicone bristles, which prevent scratches. Plus, you can put them through the dishwasher to deep clean them. Just note these don’t have any absorbency.
  • Synthetic foam: Most sponges, including the popular Scrub Daddy, are made from synthetic foam. It’s super absorbent and soft, but it can easily harbor hundreds, if not millions, of bacteria.
  • Bamboo: You can also get natural bamboo sponges, such as the Casabella Kind sponge. These sponges are made from plant-based materials, including loofah, cellulose, cotton, hemp, and bamboo.

Top Tip

No matter what kind of sponge you use, it’s worth color coding them. For instance, use blue for cleaning surfaces, yellow for dishes, orange for bathrooms, and so on.

What is the Effect of Using Dirty Sponges In the Kitchen?

The most considerable risk of using dirty sponges is that they are a source of cross-contamination. Using a dirty sponge can spread pathogens, bacteria, and other microorganisms to other surfaces. This includes other dishes, countertops, cooking surfaces, or chopping boards.

Since some of these bacteria are dangerous, they could make you ill (9). The risk is low, but it’s still there.

How Long Do Sponges Last?

Sponges that are washable or reusable may seem like they last forever, but you should replace them every two weeks. If you have a cloth sponge or a silicone sponge, you can wash and dry them more often instead of replacing them.

Absorb These Facts

Now that we’ve walked you through 10 kitchen sponge cleaning facts and statistics, we urge you to remember one thing. If you’re going to use a kitchen sponge, remember to replace it every two weeks.

That being said, we aren’t huge fans of kitchen sponges. You’re better off using a silicone sponge, dish cloth, or scrubbing brush. These host significantly fewer bacteria which is safer for you and your family.

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About the Author

Beth McCallum

Beth McCallum is a freelance writer & book blogger with a degree in creative writing, journalism, and English literature. Beth firmly believes that a tidy house is a tidy mind. She is always looking for new ways to sustainably clean and tidy her house, that's kind on the environment but effective in the house, too!