8 Things to Never Put in Your Garbage Disposal

Not all parts of the onion can go in the garbage disposal. (Photo: Alena Haurylik/Shutterstock)

The garbage disposal is a handy kitchen appliance, whisking away food scraps and making cleanup a little easier. But not every scrap of food can go into the disposal. Some foods will damage it. Other foods may make it through the disposal just fine, but they could end up clogging or damaging your pipes.

Before you clean up after your next meal, make sure you know about the foods that shouldn't go in the garbage disposal, and a few others that may make you proceed with caution before throwing them in.

Definitely not

buffalo wing bones
These bones belong in the trash, not in the garbage disposal. (Photo: gowithstock/Shutterstock)

Never put these foods in your garbage disposal because they can damage it or cause your drain to clog.

Bones: Very small bones like fish bones may be OK in a garbage disposal, but most bones will be a problem. They are very difficult to grind, and Consumer Reports says that even if they are ground up, they can end up in the bottom of some pipes, causing a potential blockage.

Onion: This one is very specific. The papery outer skin is OK to put in the garbage disposal, and most of the inside of the onion is fine. However, the fleshy layer under the papery outer skin is thin enough that it can pass through the disposal. It can then wedge in the drain, trapping foods that come after it, causing a clog.

Fibrous foods: Foods like celery, corn husks, banana peels, asparagus and pumpkin have fibrous strings that Drano says can wrap themselves around the blades of the garbage disposal and make them difficult to spin.

Vegetable peelings: Similarly, vegetable peels like potato skins and carrot peelings can create a thick paste that can build up on the blades, says Expert Plumbing Service. If they make it past the blades, they can create buildup on the wall of your pipes. If you're peeling more than one or two vegetables, be safe and toss the peelings in the compost or trash instead.

Pasta, rice, beans and oats: These foods continue to expand as they absorb water, and even the small pieces can continue to expand if they get caught in the drain, causing a clog.

Pits and seeds: The stones from fruits like peaches or avocado shouldn't go into the garbage disposal. Expert Plumbing Services suggests thinking of them the way you would wood, which you wouldn't put in the disposal, right? Seeds shouldn't go down either, including popcorn kernels. There are usually some unpopped kernels in any bowl of popcorn, so don't toss them in the disposal.

Shells: Oysters, clams, mussels and other seafood shells should never go into the garbage disposal. It just can't handle them.

Grease and oil: Your garbage disposal will be fine if you put these fats down it, but your pipes will not. They will build up and cause clogs. The fats that do manage to make it through your pipes can end up causing big problems for the public sewer system in the form of a fatberg, a large chunk of fat that clogs the sewers that's full of the things we flush down the toilet like wipes and diapers.


leftover coffee grounds
There may be better uses for coffee grounds that putting them in the disposal. (Photo: tab62/Shutterstock)

Some sources say these items are OK to put down the garbage disposal; some say they're not. I've been putting all of these down my disposal without any problems, but I'll be keeping an eye out for any issues with them from now on.

Coffee grounds: Some experts say you should never put coffee grounds in the garbage disposal, but others say coffee grounds are fine. The garbage disposal maker does recommend putting just a little into the disposal at time and running cold water on full blast to help push the grounds through the pipes so they don't clog older pipes. However, there are lots of uses for coffee grounds including adding them to soil around acidic soil-loving plants or using them as an exfoliant so you may want to give them a second life instead of disposing of them.

Eggshells: Some sources say eggshells break up into tiny little parts with sharp edges that could lodge into any buildup in the pipes, causing further buildup that could lead to a clog. However, Insinkerator says they're fine as long as you put them in slowly, maybe one at a time, and run cold water on full blast to push them through the pipes, continuing to run the water for 10 to 15 seconds after you turn off the disposal.

Citrus peels: Putting citrus peels down the garbage disposal is said to help clean the disposal and deodorize it. E.R. Plumbing Services says this is bad advice because lemon, lime, lime, orange and other citrus peels can get stuck in the disposal, creating a problem.