Do You Need to Clean Your Sponges? Here's How to Rid Them of Germs

A 2017 study found staggering amounts of bacteria inside a typical household sponge—up to 45 billion per square centimeter. Sponges are still more sustainable than paper towels, but moist ones are breeding grounds for germs. To keep them at bay, use all-natural sea sponges, which have inherent antibacterial properties, and disinfect them at least every few days. Jessica Ek, a director at the American Cleaning Institute (ACI), suggests soaking them for five minutes in a solution of one quart water and three tablespoons chlorine bleach, then rinsing and letting them air-dry.

The ACI does not recommend using the microwave to disinfect sponges: Dry ones can catch fire, plus variables like wattage and sponge size make it hard to gauge how long you need to zap them. Between washes, rinse your sponges out after each use, then wring them out well and store them somewhere they can dry—not in the sink itself. "Leaving them there to stay constantly wet will encourage bacteria to grow," says Ek.

According to the United States Department of Agriculture (USDA), you can also kill bacteria on sponges by running them through your dishwasher. Using this method, you will be able to kill 100 percent of germs lingering on the surface of and inside these cleaning essentials. Simply place the sponge on the top rack in the dishwasher with the drying cycle on and let the appliance do the work.

Finally, it's important replace them every few weeks—or sooner if they begin to smell. If you notice the sponges starting to fall apart by that point, then it is also time to toss them out. Another pro tip? Instead of using the same sponge for all of your kitchen tasks, like washing the dishes and wiping off counters, consider using different pieces to avoid contamination.