Attached to the underside of a kitchen sink's drain, a garbage disposal works by chewing up food scraps that are fed down the drain with a heavy flow of water. A shredder breaks the food down in the grinding chamber, then an impeller arm and plate force the liquid and particles down the drain. Dishwasher drain water also runs through the garbage disposal so that any large particles are chewed up and drained away.

The familiar continuous-feed style is activated by a switch as you run the water. Most garbage disposals have electric-powered motors.

Garbage disposals work best if you:

	Use cold water when grinding food (hot water can melt fats in food, which clog the mechanism and pipes)
	Do not overfill the unit
	Do not pour bleach, drain cleaners, or other chemicals into the unit
	Do not grind overly fibrous materials, bones, or coffee grounds (check the owner's manual) or materials like glass, metal, or rubber
	Run water before, during, and after you use the disposal