11 Things You Should Never Put in Your Garbage Disposal

Updated on Mar. 06, 2025

A garbage disposal is an amazing appliance—until you drop the wrong thing down the drain. Save yourself some serious hassle by avoiding these items.

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Garbage disposals seem indestructible, but don’t be fooled. The mechanisms are sensitive, and the wrong thing dropped down the drain can put your disposal out of commission, resulting in an expensive bill from your plumber (up to $430 on average!). To seek out the culprits, I interviewed our family plumber for his tips on how to avoid a garbage disposal fiasco.

John Porter is the owner of his own plumbing business, JP Installations Services LLC, which has been in business in central Wisconsin for almost 30 years. He has also worked for several appliance stores, including Sears and Best Buy, and has installed close to 1,000 garbage disposals.

So, what are those forbidden garbage disposal items? Well, take it from a plumber…

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Horizontal photo of female hand pulling out used coffee filter, from coffee machine, with stone counter top in background
Shutterstock/tab62

Coffee Grounds

One garbage disposal myth that Porter debunked was using coffee grounds to treat a smelly garbage disposal. Porter says coffee grounds could clear your disposal, but there’s still a chance they could clog your drain. Even when ground, coffee beans stay hard and become even denser in water, resulting in potential blockage. Better to play it safe and put your grounds in the trash or compost instead. (Psst: If you’re set on repurposing those grounds, it is possible clean with coffee grounds!)

If yours is smelly, Porter recommends cleaning your garbage disposal with orange and lemon peels: “If I have an orange, I’ll keep a couple peels and run [the disposal] at night dry with orange and lemon peels and let them sit overnight even if they’re not totally ground up.” He also recommends purchasing disposal cleaner at your local hardware or big box store.

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raw potato peelings in kitchen sink with stream of water from faucet
Shutterstock/Maria Dryfhout

Potato Peels

Porter says potato peels cause problems. “Some of the worst [offenders] are starchy material like potato peels. Anything that might stick to your drain wall can be a problem.” In fact, he remembers having to go back to a house ten minutes after installing a garbage disposal because the user got potato peels stuck in the disposal. Don’t risk it, throw those peels in the trash or compost bin!

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eggshell;
Shutterstock/Avelina

Egg Shells

We’ve all heard the proclamation that egg shells are not only safe to put down the disposal, but that they actually help sharpen the blades. Unfortunately, this myth could do some serious harm to your disposal and cost you big. Once the shells are ground, the tiny particles can stick together and clog your disposal and pipes. Not only that, but the thin membrane inside the shells can also get trapped over your drain, catching other items and resulting in a clog.

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Onion peeled and skin on wooden background
Shutterstock/Marcin Wos

Onion Skins

Like potato skins, onion skins are safer in the compost. The thin membrane underneath the outside dry layer is the main culprit, as it can get past the blades and become stuck over the drain like a small net. If it eventually traps more items, it could result in a drain blockage.

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Three fresh corn cob on wooden table
Oksana Shevchenko/Shutterstock

Corn Husks

On the subject of corn husks, Porter says “Definitely not! Too fibrous, and it would plug [the disposal] up in a heartbeat.” He adds that it’s just generally a good idea to stay away from anything fibrous. And be wary of peels, like banana peels and even carrot and celery peels.

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chicken bone on black plate
Shutterstock/gowithstock

Bones

While your garbage disposal can handle a lot, there are some things it’s just not cut out for—bones being one of them. Although some people claim bones will help keep your blades sharp, Porter says it’s just not the case: “Anything you put down there will eventually wear it out.”

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Cherry Seeds with Stalks / Fruit Garbage
Shutterstock/Alp Aksoy

Pits

Just like bones, fruit pits are way too tough for your disposal to deal with. If you accidentally drop a hard object down, or if your garbage disposal jams, Porter says you can possibly deal with it yourself. Many times, a small jam will trip the breaker on the bottom of the disposal. “Hit the breaker, it’s just a little push button you don’t have to push too hard, turn it back on and see if it works.” If it doesn’t start up, Porter advises going in from the top using a screwdriver or a small crow bar to try and get the blades to move and clear out whatever is blocking the blades from turning. You can also purchase a garbage disposal retriever tool, which has a flashlight attached and a set of pincers to grab the dropped item.

But safety should always be first. “If you’re afraid to touch anything or afraid of getting your hand hurt then I would call your plumber, especially if you can’t get [the blades] to move.”

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Dry rolled oat flakes oatmeal on old wooden table
Regreto/Shutterstock

Oatmeal

The danger in putting oatmeal down the drain is its tendency to expand. Anything that grows once it absorbs water, like pasta, oatmeal and breakfast cereal, is something to be wary of. If you simply have to put it down the garbage disposal, Porter says the trick is to simply use lots of water, and go slowly. “[Garbage disposals are] great for cleaning up your sink if you have leftover meat or noodles. And it’ll take care of lettuce and things like that. But the most common mistake is people filling it up and then running it. They’ll think of it as a food processor. They should be running water as [the disposal] is running and pushing stuff down the drain.”

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Homemade sauerkraut with cumin in a glass jar
iuliia_n/Shutterstock

Sauerkraut

If you’re a fiend for the German dish of sauerkraut, just make sure it doesn’t get anywhere near your garbage disposal. Similarly to potato peels, sauerkraut can stick to the walls of your garbage disposal and create a blocked blade. So enjoy your sauerkraut brat, but make sure your scraps are staying out of the sink.

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paint cans
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Paint

Paint might seem innocuous since it’s in liquid form, but it’s dangerous to pour any strong chemicals down the drain. Like liquid plumber, it can cause problems in your pipes. Furthermore, if you have a septic system or live above a well, you definitely don’t want those chemicals around. Porter suggests disposing of paint by leaving the covers off the buckets until the paint hardens and dries before throwing it out. Or, if you have a larger amount, pour the paint onto cardboard and let it dry.

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garbage
Shutterstock/TY Lim

Trash

It’s easier than you would think to accidentally put trash down your disposal. Since a lot of people pack up their produce with plastic bags and twist ties, sometimes these items can end up in the sink, and then down the disposal. Once they’re down there, they can definitely cause a jam.

So, what other random dropped items end with a call to the plumber? Well, Porter says he often gets called for loose change down the disposal. In that case, the problem depends on the size of the coin: “A nickel will jam it up. A dime won’t, but it’ll just sound like a rocket ship taking off.”

Porter’s rule of thumb? If there’s a doubt, throw it out: “Any questions, don’t put it down there.”