It’s Confirmed: This Kitchen Item Can Harbor More Bacteria Than A Toilet Seat

Between preparing and handling food, piling dirty dishes in the sink and constantly wiping up spills and crumbs, you can see how your kitchen is a prime spot for germs. Yet the germiest item in your kitchen may surprise you, because it’s what you use to keep it clean.

“A dirty sponge can actually contain more bacteria than a toilet seat,” said Darin Detwiler, a food safety expert and professor at Northeastern University. “Each use spreads germs instead of removing them, turning your efforts to clean into an unintentional act of contamination.”

Because they are “warm, damp and full of food particles,” they are “ideal conditions” to fuel bacterial growth, he added.

We talked to experts about the risks of using a dirty sponge, how to properly clean it, and when to replace it — plus a few other unexpected kitchen items where you may find bacteria lurking.

A sponge is “used often, wet most of the time, and doesn’t get properly cleaned,” said Becky Rapinchuk, cleaning expert and founder of Clean Mama.

Additionally, because sponges are porous, they “have an incredible amount of surface area,” explained Jason Tetro, a microbiologist and author of “The Germ Code.” “Bacteria can coat the entire surface and even grow three-dimensionally.”

The amount of bacteria can double in as little as 30 to 60 minutes in some cases, he said. In this study, “tens of billions [of bacteria] were found for every cubic centimeter.”

Fecal bacteria is also often found in dirty kitchen sponges, added Charles Gerba, a microbiologist and professor at the University of Arizona. For example, fecal bacteria can transfer to the sponge when you wipe up surfaces where raw meat was placed or handle raw meat and then touch the sponge.

Another way fecal bacteria could end up on the kitchen sponge is if you’re not washing your hands properly, Tetro said. (Proper hand-washing includes wetting your hands with water, lathering with soap, scrubbing for at least 20 seconds, rinsing and drying, according to the Centers for Disease Control and Prevention.)

While a lot of the bacteria in our environment is harmless, “there is always the chance for more troubling bacteria, especially from raw meat juices,” Tetro said. If you’re exposed to a high enough number of these pathogens, you’re at risk for getting sick.

Detwiler listed salmonella, E. coli, campylobacter and listeria as some of the bacteria likely to live in sponges, noting they “can lead to severe gastrointestinal distress, dehydration and even life-threatening complications, particularly in young children, older adults and those with weakened immune systems.”

The other risk with sponges is they don’t just contain bacteria, but can spread it around your kitchen.

“Each time you wipe a countertop or rinse a dish, you risk transferring millions of harmful microbes to your hands, cooking tools and food,” he said.

There are a few different methods our experts suggested, but they all agree: It’s key to stay on top of cleaning, disinfecting and replacing your kitchen sponge.

“I recommend putting it in the top rack of your dishwasher nightly,” Rapinchuk said. “Wring it out in the morning and let it air-dry.”

Another option is to make a solution of 1 quart water and 3 tablespoons chlorine bleach, and soak the sponge for five minutes, suggested Kristin DiNicolantonio, a senior director at the American Cleaning Institute. Rinse the sponge with water, and let it air-dry. (Don’t forget to wash your hands after.)

In terms of how often to replace your kitchen sponge, DiNicolantonio recommends every two to three weeks (depending on how often you use it) or at the first sign of odor or damage.

“An even safer alternative is to use brushes, which can be thrown in the dishwasher, or washable dishcloths, which dry faster and can be disinfected in the laundry,” Detwiler added. (A study showed that dishwashing brushes have lower amounts of bacteria than kitchen sponges.)

While the kitchen sponge contains the most bacteria (by far), we asked our experts about a few other items in the kitchen that harbor bacteria and aren’t often cleaned enough.

“If there’s a small spill somewhere [in the fridge], the bacteria will start growing and spreading to other items,” said Kadi Dulude, owner of Wizard of Homes NYC. “I’d recommend cleaning up spills immediately when they happen and then … [wiping down] all possible surfaces before each grocery trip when the fridge is somewhat empty.”

She advises using a vinegar-water mix to clean the fridge because it also helps get rid of smells. Lastly, using fridge liners (non-slip and washable) can make it easier to keep the shelves and drawers clean.

“Cutting boards come in contact with raw meats, and when these juices are left to sit on surfaces, they’ll start growing bacteria,” Dulude said. “Do not leave in the sink. … You should wash and thoroughly scrub the cutting board right after using it.”

She suggests using natural wood boards instead of plastic because it’s been “proven that wood has natural antibacterial properties to inhibit bacterial growth.” Also make sure to use different cutting boards for vegetables and meats, she added.

Countertops carry the same risk for bacteria after raw meats and vegetables have been sitting on them. Tetro advises using soapy water to clean after every use, and if raw meat has been on the surface, use a “disinfectant that is safe for food-contact surfaces.” Rinse well after.

From washing pots and pans to rinsing produce, your sink is used for many things and lots of bacteria could be lingering in there, according to the U.S. Department of Agriculture.

“Also people often open wrapped meat products over the sink to avoid getting juice from the product on the countertop,” which can lead to more bacteria, Gerba explained.

He said it’s best to disinfect the sink with a bleach wipe or kitchen disinfectant, especially after preparing raw meat products. Additionally, NSF recommends disinfecting the sink once or twice a week and kitchen drains and disposals once a month by pouring a bleach water solution down the drain (1 tablespoon household bleach and 1 quart of water).

Food safety “starts in our own kitchens,” Detwiler said. “The choices we make (whether it’s replacing a sponge … or properly washing our hands) could be the difference between a safe meal and a preventable illness.”