The main odor problem you will experience with your garbage disposal is the smell of food. The odor of whatever you most recently tossed into the drain can linger. If you were cooking with seafood or pungent herbs, that odor can be offensive after a while. You might also notice a bacterial or rotting smell. This occurs when food inside your garbage disposal starts to spoil and bacteria grows and spreads on it.
The source of the smell in your garbage disposal could be food sitting in the bottom of the disposal that has not washed down the drain. As it lingers and spoils, it sends a foul odor up through the drain and into your kitchen. Sometimes food splashes up onto the underside of the splash guard, which keeps food from flying up out of the disposal when you run it. As food accumulates on the back of the splash guard, it begins to spoil and eventually the smell becomes so strong you'll notice it.
To get rid of garbage disposal odor caused by food caught in the disposal itself, cut a lemon into quarters and gather a double handful of ice cubes. Place the ingredients into the disposal and run it without water for about 15 seconds. Let the ice and lemon mixture sit for 30 minutes, and then run the disposal with water to clear it all away. The lemon will neutralize the odor and the ice will clear away food particles. To clean the splash guard, consult your owner's manual for the garbage disposal. Most can be removed by tugging them up and out of the sink. Scrub it clean with soapy water, removing all lingering food particles.
Run plenty of water when using the unit to reduce the risk of odors developing in your garbage disposal. Run the water while the unit is functioning, and then continue to run it for 20 seconds more. This will flush all food particles down the drain and prevent them from building up inside the disposal. When cleaning the splash guard, disconnect the garbage disposal from its power source. This eliminates the risk of injury while you are pulling the splash guard out and replacing it after it's clean.