The handy kitchen garbage disposal is useful for getting rid of a variety of food scraps and waste that might otherwise create unpleasant smells in the kitchen. However, many foods can actually damage your disposal or render it useless.
A common misunderstanding about garbage disposals is that the device includes "blades," when in actuality it contains a ring of teeth-like shredders that grind the food and force it down the drain. While there's no real way to sharpen these shredders (which are still often referred to as blades), keeping them clean is key to an efficient garbage disposal.
Avoid putting these things down your garbage disposal to help keep it running smoothly.
The strings of celery, artichokes, asparagus, lettuce, corn husks, carrots, onion skins and potato peels can wrap around the grinding teeth, preventing proper operation of the motor. If you feel you must put fibrous foods into your disposal, do so in very small quantities, and run cold water before, during and after operating the unit.
Grease, Fats and Oils
Greasy foods will distribute a film over the shredding teeth, diminishing their effectiveness. Eventually, the grease will begin to decay, causing an unpleasant odor in the kitchen. Pouring grease into a garbage disposal can result in clogged drains when the grease solidifies (regardless of how much hot water you use).
Some people claim that egg shells sharpen the blades of the unit, but this is not true. The shells' stringy membrane layers can wrap around the shredder ring, and the shell itself will be ground to a sand-like consistency capable of clogging pipes.
Pasta, Rice, Potatoes and Beans
Even small particles of these foods will swell with water to form a paste-like substance, and eventually clog the trap.