9 Items You Should Never Toss Into Your Garbage Disposal, According to Experts

Garbage disposals make it easy to dispose of leftover food scraps and unused cooking ingredients. However, not everything is suitable for the disposal. Certain common items can cause blockages, leading to expensive plumbing repairs.

“As a seasoned plumber who has spent years dealing with the aftermath of misused garbage disposals, I can assure you that many homeowners don't realize the harm that common items can cause to their disposals,” says Mehdi Khachani, CEO of JMK Plumbing and HVAC, based in Miami.

Avoid putting these foods in your disposal to keep your kitchen running smoothly.

Oatmeal

One food that may surprise you for being unsuitable for the garbage disposal is oatmeal. Although it appears to go through easily when wet, it can actually damage your disposal when it dries out. Instead of tossing it in the disposal, consider putting oatmeal in your compost or trash.

“Oatmeal may seem harmless for your garbage disposal blades when it’s wet,” says Joe Hammer, owner of SAK Electric Plumbing Inc. in Phoenix. “The issue arises when oatmeal hardens; it becomes very tough. Any leftover oatmeal in your garbage disposal will solidify and can cause damage to the disposal blades over time.”

Eggshells

Eggshells are another common food people often dispose of in their garbage disposals. However, these seemingly harmless shells can cause significant damage to the disposal, getting caught in parts and possibly leading to clogs.

“Eggshells can break down into tiny, gritty particles that contribute to pipe blockages,” says Shlomo Cherniak, owner of Cherniak Home Services in Baltimore. “This leads to clogs and hampers the efficiency of the disposal. The eggshell membrane wraps around the impellers, causing substantial blockages.”

Instead of discarding your eggshells in the disposal, add them to the compost or trash to avoid damage.

Fibrous Vegetables

Fibrous vegetables can wreak havoc on your garbage disposal, with long strands of vegetable matter wrapping around the blades. Keep vegetables like celery, corn, and asparagus out of the disposal, and instead place them in the compost or trash.

Celery is actually one of the worst vegetables to put down your garbage disposal. Although it may seem harmless to most homeowners, the stringy fibers of celery can wrap around the blades, causing damage. Hammer advises against putting it down the disposal.

Bones

It might seem obvious, but even small bones can be harmful to your garbage disposal. Some people believe that smaller bones are less damaging, but they can still cause significant harm to the blades. Avoid throwing any type of bone in the disposal.

Even small bones can cause serious damage to your garbage disposal's motor and blades, leading to malfunctions or complete breakdowns. As Khachani suggests, toss bones in the trash instead to keep your disposal running smoothly.

Coffee Grounds

Coffee grounds might seem harmless due to their small size, but the leftover remnants of your morning coffee never fully dissolve in the sink.

According to Cherniak, instead of dissolving, the coffee grounds clump together, forming a dense paste. This paste can get trapped inside the pipes, leading to clogs and slow drainage.

Coffee grounds are actually excellent for composting, as they enrich the soil with nitrogen.

Potato Peels

Potato peels, like coffee grounds, should not be put down the sink. They contain starch, which turns into a thick paste that can easily block your pipes. Instead, toss them in the compost or trash.

Cherniak points out that potato peels contain a lot of starch, which transforms into a thick, sticky paste. This paste can block your garbage disposal and obstruct your pipes.

Fruit Pits

While fruit pits are natural, they’re not suited for your garbage disposal. The hard centers are better off in compost rather than clogging the blades of your disposal.

Khachani warns that hard pits from fruits like peaches, cherries, or avocados are too tough for your disposal blades to handle. They can easily get jammed or cause damage.

To keep your garbage disposal running smoothly, dispose of fruit pits in the compost or trash, not down the drain.

Grease and Oil

Anyone who has cooked with grease or oil understands how messy it can be. While it may be liquid at first, oil leaves behind a thick, sticky residue in pipes, leading to trapped food and unpleasant odors in your disposal.

Cherniak explains that when you pour grease or oil down your disposal, it solidifies into a sticky coating. This buildup causes blockages and foul smells by trapping other debris.

Dispose of oil and cooking grease in the trash to maintain your garbage disposal’s health and avoid clogs.

Pasta and Rice

Avoid putting pasta and rice in your garbage disposal. Whether cooked or uncooked, these foods tend to expand and swell inside pipes when they come into contact with water, leading to clogs and drainage issues, explains Cherniak.

You can compost pasta or rice with a few precautions, or simply dispose of them in the trash.