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.

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.

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.

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.