What Can & Can't Go Down a Garbage Disposal?

A garbage disposal keeps waste food out of your garbage and ultimately out of the landfill. But even though this convenience is a powerful food-chopping machine, it has limitations. Some food items can clog it quickly, others clog it slowly, and some leave food deposits that encourage mold growth. On the positive side, some of the things you drop into the disposal can actually help it to function more efficiently and smell better.

Under the sink.
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What Can & Can't Go Down a Garbage Disposal

Avoid Binding the Rotor

A garbage disposal consists of a rotor mounting inside a canister with abrasive sides. The impellers on the rotor force food toward the edges, where it gets ground and flushed through the small gap between the rotor and canister. There isn't much room in the gap, and fibrous foods, such as celery, onion skins, artichokes and corn husks can easily get stuck there, so avoid them. Large bones also get stuck easily, but your disposal may be able to handle small ones, such as chicken and fish bones. Check the owner's manual. Never put anything made of glass metal or plastic into a garbage disposal; you should even avoid paper.

The Goop Factor

Some food items grind easily, but they leave residues that accumulate and eventually cause clogs. Potato peels and rice are two examples that can necessitate troublesome cleanup procedures. You shouldn't pour grease or fats into the drain, but small amounts are inevitable. To prevent them from liquifying and collecting in the rotor and canister, where they cause clogs and mold, avoid pouring hot water in the drain. Coffee grounds won't clog the disposal, but they accumulate in the pipes to cause clogs there and are best avoided.

Things Your Disposal Likes

Even if you avoid all the items your disposal can't handle, clogs can still happen, because small food items can still get stuck between the rotor and canister. Grinding certain hard items, such as small bones and ice, can help loosen these. Some plumbers recommend regularly putting egg shells in the disposal to clear potential blockages, but others don't, advising that the shell membranes add to the goop factor. Flush whatever you put in the disposal with cold water -- failure to run the water while using the disposal is almost certain to result in a clog.

Garbage Disposal First Aid

If you like fresh smells in the kitchen instead of musty odors -- and who doesn't -- cut two or three oranges or lemons into pieces and grind them; citric acid is a natural deodorizer. You can also deodorize your disposal and kill mold by pouring in 1/2 cup of baking soda and 1/2 cup of vinegar when you run ice through it. If a clog does develop, it's safer and more effective to clear it with natural products, such as a combination of vinegar and baking soda, than to use a caustic drain cleaner. They can damage the pipes and spatter back at you when the disposal is running, possibly causing burns and eye damage, so it's best to avoid them.

Chris Deziel

Chris Deziel

Chris Deziel has a bachelor's degree in physics and a master's degree in humanities. Besides having an abiding interest in popular science, Deziel has been active in the building and home design trades since 1975. As a landscape builder, he helped establish two gardening companies.