What’s the germiest room in your house? Most people mistakenly think it’s the bathroom, according to a new study from NSF International, an independent public health and safety organization. But when researchers conducted a swab analysis of 30 everyday household items in 22 different homes—measuring the levels of yeast, mold, coliform bacteria (which includes Salmonella and E. coli) and Staph bacteria—they found that the kitchen took top billing.
Here are the top 10 biggest individual offenders—starting with the worst item—plus tips on how to clean up your act.
The sponge you use to clean your dishes and countertops may actually be the dirtiest thing in your home, says Rob Donofrio, PhD, director of microbiology at NSF. That’s because sponges pick up bacteria while you clean and are often not sanitized before their next use. Seventy-five percent of the tested sponges had coliform prevalent, a bacteria that indicates fecal matter, according to the NSF International study. To disinfect a sponge, soak it in water and then heat it in the microwave for one to two minutes or carefully pour boiling water over it. Rinse with cool water before using it again.
Sinks are germy due to lingering sponges and improper cleaning methods, says Donofrio. Filling the sink with soapy water every time you do dishes isn’t enough to keep it clean, either. Wash your sink separately, and be sure to follow the instructions on your cleaning supplies. If the bottle says to let the soap sit for a minute before rinsing, do it.
There are two reasons why this common bathroom item is grimy: They’re usually kept close to the toilet—which sprays fecal matter when flushed—and many people forget to wash them, says Donofrio. He recommends sticking holders in the dishwasher with the rest of your dishes.
Pet bowls were the only objects found to be carrying E. coli. Just like sponges, bits of food can get stuck on them, and they’re often neglected when it comes to washing. If you keep pet bowls in your kitchen, you’re also at risk of introducing more coliform to your kitchen and eating areas. “Treat them like your own bowls,” says Donofrio, and wash them regularly.
These are tricky. Some coffe makers come with a self-clean feature, but what do you do if they don’t? You need to take the pieces apart and clean each of them. If you don’t clean the water reservoir, you’re digesting germy coffee, says Donofrio.
When it comes to cleaning duties, this commonly used feature often gets neglected. Remember, you touch it after you use the toilet, says Donofrio, so it’s important to thoroughly wash it—bacterias such as coliform can cause staph infections and other dangerous viruses.
The belief that your dog’s mouth is cleaner than yours isn’t necessarily true, says Donofrio. So remember to clean their toys. If it’s rubber, use a disinfectant or put it in the dishwasher. If it’s cloth, throw it in the washing machine.
If you haven’t noticed, the kitchen is the germiest of all household places. Knobs—most often dirtied by our hands—are just another object forgotten in our cleaning routines. Besides regularly wiping these down, keep your hands clean when cooking, especially when handling raw meat.
The abrasions on cutting boards trap moisture and food particles, making these boards an ideal breeding grounds for organisms. In the NSF study, 18 percent of homes had coliform on their cutting boards. Clean yours thoroughly after each use with hot water and disinfectant.