While your sponge spends a lot of time submerged in water and other cleaning products, it’s not actually self-cleaning, which means you have to give it some TLC. “Cleaning a sponge weekly will help prevent you from spreading bacteria from dish to dish as well as to your sink and countertops which can help keep you and your family from getting sick,” our friends at the American Cleaning Institute (ACI) tell us.
According to a 2017 study by Scientific Reports, kitchen sponges are a hotbed for germs and bacteria. “We found 362 different species of bacteria, and locally, the density of bacteria reached up to 45 billion per square centimeter," microbiologist Markus Egert, who led the study, told NPR. "That's a very huge number of bacteria. There's hardly any habitat on Earth where you'll find similar densities of bacteria, except for the human intestinal tract." Yikes!
While sanitizing your sponge every week makes it less gross, this handy kitchen helper still won’t survive forever. For optimal hygiene, the ACI also recommends folks replace a sponge every two to three weeks, or as soon as it starts to look and smell like it has seen better days.