10 Things You Should Never Put in Your Garbage Disposal

White plate with fork, pasta noodles and sauce next to garbage disposal in sink

The Spruce / Sarah Lee

Garbage disposals are great time-savers and they minimize kitchen odors. With their push-button convenience, garbage disposals may seem like magic devices that make everything disappear. But disposals are not designed to handle every type of waste. Use your garbage disposal as a supplement to composting organic matter—a far better choice—and be sure to avoid putting certain items down it.

Animal Fats and Grease

Fat and grease byproducts of cooked meat start as liquid, then quickly congeal and harden into a white paste that your garbage disposal and drain pipes cannot eliminate.

Strips of bacon covered in grease on paper towel and white plate closeup

The Spruce / Sarah Lee

Cooking Oils

While cooking oils such as canola, vegetable, or olive oils don’t immediately congeal like animal fats, over time they do create a thick, sticky gel that clogs up your disposal.

Tip

Some garbage disposal warranty clauses state that the warranty is invalidated if the unit breaks down due to the user grinding incorrect materials.

Coffee Grounds

A few coffee grounds in the garbage disposal are fine, but dumping a lot all at once can clog it up. Coffee grounds clump and can form a mass that’s difficult for the disposal to break up and move out.

Used coffee grounds scooped in wooden spoon closeup

The Spruce / Sarah Lee

Large Pits

Pits from apricots, plums, and avocados (or any large pit) should never go down the disposal. Rather than gunking up the system, it’s more that the disposal will not grind them down. Put an avocado pit down your disposal, and it will bounce around forever until you decide to take it out.

Hot Water

Do not use hot water when grinding food waste. It is perfectly fine to drain hot water into the disposal between grinds, but don’t use hot water when grinding food matter. Even if you're studious about preventing fat and grease from going into the disposal, food still does have trace amounts of it. Hot water liquifies residual fats and greases, spreading them out in a thin layer along the system.

Large or Thick Bones

Large bones resist the centrifugal pounding action of the garbage disposal. They won’t break up, requiring you to remove them.

Warning

Always unplug the garbage disposal to disconnect it from power completely before removing items from the grind chamber.

Glutinous Materials

Pasta, rice, bread, and oats may be pantry staples, but it’s best to keep them away from the garbage disposal. Any food material that becomes glutinous upon contact with water can gunk up your garbage disposal. 

Random strands of fettuccine or grains of rice are no problem. But when you start forcing mounds of oats, rice, or wheat-based products down the garbage disposal, you’ll quickly see the limit of your unit’s operating capacity. Hot water only worsens the problem, so be sure to use cold water if you’re trying to force along any of this glutinous food matter.

White plate with leftover pasta noodles and sauce with fork on top

The Spruce / Sarah Lee

Peanut Butter

Peanut butter, sticky enough to resist the dishwasher on heavy cycle, doesn’t fare much better in the garbage disposal. Avoid putting peanut butter in the garbage disposal. It’s so oily and sticky that the water and the grinder cannot expel it.

Shells

Clam or oyster shells are too hard for the garbage disposal to effectively break up, even to the point of damaging the unit. Most manufacturers single out these types of shells as being no-no’s for garbage disposals.

Stringy Vegetables

Celery, corn husks, artichokes, rhubarb, string beans, banana peels, and any other type of vegetable that’s stringy or excessively fibrous should never go into the garbage disposal. The strings can be caught in the mechanism and be difficult to remove.

Things You Should Put Down Your Disposal

Some items should be put down your garbage disposal to keep it running in top condition. (Some can even help it smell fresher.)

Cold Water

Run cold water, not hot water, during grinds. Cold water keeps any residual fats and greases in solid form, and this helps to send them down the drain pipes.

Disposer Cleaner/Degreaser

Biodegradable garbage disposer cleaners or degreasers scrub the grinding mechanism and the grinding chamber. Use monthly or as needed.

Small Pits and Bones, Ice Cubes

Manufacturers recommend putting hard materials such as small fruit pits or small bones down the disposal, as they create a scouring action in the grind chamber. Some tiny particles may remain, but they will eventually wash away.

Ice cubes can clean the chamber, too, but have the added benefit of being able to melt away afterward.

Citrus Rinds

Grinding lemon or lime rinds is a classic method of neutralizing garbage disposal smells and one that’s recommended by disposal makers.

Dish Soap

If you have a few last squirts of dish soap you’d like to get rid of, dump them down the garbage disposal and run with cold water. It’ll help clean up the disposal and leave a fresh scent.