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The Big List of What Not to Put in a Garbage Disposal

egg shells

There are certain items (some of them surprising) that should NEVER go in a garbage disposal unless you WANT to spend an afternoon under your sink. Here are 16 things to avoid putting in your garbage disposal – and a few rules as to when you can make an exception.


Pile of chicken bones on a platter next to 2 bowls of dipping sauce.

Putting some hard bones in your garbage disposal is nothing but a trap. Not only do they clog the sink, but they will also damage the appliance in the long run. Here, some people may argue that they safely grind fish bones with their disposal unit. We do acknowledge that it is possible for high-powered devices to grind small quantities of fish bones but they can’t crush harder bones.

Corn Husk

shucked ear of corn laying on wooden table next to pile of husks

Corn husk produces a substantial amount of fibrous waste that should never go down the drain. These fine threads of corn silk can bind garbage disposal by wrapping around its blades. For this reason, you should ALWAYS put this robust husk in the garbage can.

Coffee Grounds

wooden spoon of wet coffee grounds on wooden table next to spilled bowl of grounds.

Coffee grounds are a suitable alternative for sharpening the grinding components of garbage disposal. Similarly, they can freshen up a foul-smelling kitchen. Despite all that, they should NEVER be put into your sink. This is because they can clog your pipeline really badly by forming a dense, pasty wad. You can get a clearer idea about that by analyzing some used coffee grounds out of a strainer.

Egg Shells

broken brown egg shells on wooden surface

You may have heard that egg shells are beneficial for sharpening the blades of garbage disposal. There is no scientific theory to back these claims but these shells can have an adverse impact on your unit. The thin membrane on the inside of egg shells can jam the impellers of the appliance. This can result in a number of different problems like clogging.

Fibrous Vegetables

head of celery with some cut and chopped on a cutting board

A lot of everyday vegetables (celery, asparagus, carrots, etc.) are fibrous in nature. The long stalks have all the potential in the world to clog your garbage disposal. Similarly, they can damage the unit as the machine needs to work to its limit. In case of an emergency, you can cut these fibers in small, manageable pieces before throwing them into the sink.


Variety of hands lifting up in the air waving at the camera

It is against the laws of common sense to stick your hands inside an operating garbage disposal. Although common sense is not so common, most people know what a disposal unit can do. However, young kids are not aware of the dangers and can harm themselves. In these circumstances, it is critical to ensure that they are not around the kitchen when you are using this appliance.  


bowl of mixed nuts on wooden table

It might not be a good idea to throw down nuts (especially peanuts) down your garbage disposal. The best possible example to understand the consequences is that of a nut grinder. This machine is used to make peanut butter by spinning and mashing peanuts into a thick paste. This is exactly what will happen inside your disposal unit when you put nuts into it. Ultimately, this paste-like material will clog your drain.


wooden bowl full of oats with a wooden spoon sitting on burlap with stalk of oats next to the bowl

Despite its small size, oats are another massive threat to your garbage disposal. It is quite possible that uncooked oats slip through the blades of your disposal unit. In this case, they will keep accumulating into the pipeline until the drain clogs completely. This lack of knowledge can cost you substantially, either in the form of plumbing costs or a new device.

Oil and Grease

Bottle of cooking oil laying on side with outer cap laying on table to reveal safety cap.

Grease and oils are probably the most vicious enemies of your garbage disposal. You will never realize that something is wrong with the unit because the blades will be spinning. Likewise, some people think that oils can be flushed easily as they don’t need any grinding.

The problem with these materials is their stickiness. Slowly but surely, they keep on filling the small gaps on the impellers. Not only do they affect the efficiency of the grinding ring, but they also clog the drain by solidifying there.

Onion Skins

peeled onions on a cutting board laying next to pile of onion peels.

Just like egg shells, onion skins also have a thin membrane that can escape the blades of your device. Although they don’t do any damage to your garbage disposal, they can choke your drain. They act as cargo nets and keep on catching more items to clog the sink. In order to avoid any inconvenience, you should ALWAYS throw onion skins in a trash can.

Pits and Seeds

One whole peach and a halved peach  on a cutting board revealing the peach pit.

Seeds of some delicious fruits can be a little hard to grind. For instance, peach and avocado have incredibly hard pits in their center. It is very much impossible to cut them with a knife. Similarly, garbage disposals can’t grind such a solid pit.

Even if your unit succeeds in grinding these pits a couple of times, the grinding components of the machine will get damaged. Therefore, save your hard-earned cash by throwing such seeds in garbage cans.     

Potato Peels

Set of hands peeling potatoes on a wooden table over a pile of potatoes and peels

Once potato peels are ground inside garbage disposal, they create a gum-like starch paste. This sticky substance glues to the rotating grinders of the unit and damages them. If that’s not enough, they can also clog your drain by collecting other waste materials (like onion rings). Having said that, you can grind little quantities of potato peels occasionally.


Whole and cut pumpkin on a wooden table with a knife.

Have you ever used pumpkin for a Halloween party? If yes, you would know how sticky a pumpkin can be. Disposing such a slimy item into your garbage disposal is nothing less than suicidal. Not only will it jam the grinding blades, but it will also form a dogged clog in the drain. Once you have made this mistake, the only possible way to remove the clog is by dismantling the pipeline.

Rice and Pasta

Variety of dry rice and pastas on a wooden surface with a wooden spoon full of rice

It is common information that rice and pasta expand when they get wet. These swelling items are simply destructive for garbage disposal because they can clog it. These stubborn clogs can be very difficult to clean. In addition to that, these food items also form a slimy paste that sticks with the grinding walls. This can also do severe damage to the disposal unit.   


Variety of muscles, clams, and shrimp with parsley, tomatoes, garlic, and peppers, on a wooden table.

A lot of people believe that it is safe to use garbage disposal for grinding seafood but that’s not true. Most of these foods are so dense that they can’t be ground properly. As a result, they form a gluey, white-colored clog that will choke your sink. On the other hand, some of these shells (e.g. shrimps) are so small that they go straight into the drain. Using a trash bag is a much safer and effective option.


Fork, spoon, knife and napkin, tied with twine, a sprig of rosemary and a paper tag on a wooden table.

Quite obviously, no one would purposefully put utensils in their garbage disposal. Despite that, they can sometimes make their way down to your disposal unit. The mistake of dropping a steel utensil in your garbage disposal can cost you hundreds of dollars because it destroys the grinding blades. In order to avoid this accident, you should make sure that everything’s clear before starting your disposal.

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