Garbage disposals are one of those everyday conveniences most homeowners don’t think about—until something goes wrong. And when they do, repairs can range from inconvenient to expensive.

As a real estate broker, I see firsthand how small maintenance habits can impact a home’s condition, inspection results, and even resale value. The good news? Many garbage disposal issues are completely preventable.

Here are the top 10 things you should never put down your garbage disposal—starting with one that surprises almost everyone.

1. Eggshells (Yes, really...)

Many homeowners have heard the myth that eggshells “sharpen” garbage disposal blades. In reality, garbage disposals don’t have blades at all—they use blunt propellers to grind food waste.

Eggshells can actually cause problems in two ways:

• The thin membrane inside the shell can wrap around the propeller mechanism, slowing or jamming the unit.

• The gritty particles can combine with grease and other debris to form clogs further down your pipes (eeww...I've seen these on sewer scopes, its not pretty).

Better option: Compost eggshells or throw them in the trash.

2. Grease, Oils, and Fat

Grease may go down as a liquid, and you can run hot water as long as you want, but it doesn’t stay a liquid. As it cools, it solidifies and coats your pipes, eventually causing serious blockages. This is one of the most common causes of plumbing issues, especially in kitchens.

Better option: Let grease cool, then dispose in the trash.

3. Coffee Grounds

Coffee grounds don’t break down well. Instead, they accumulate into a dense, sludge-like material that can clog pipes over time. Even small amounts, repeated daily, can create problems.

Better option: Compost them—they’re excellent for soil.

4. Pasta, Rice, Bread, and Other Starchy Foods

These foods expand when exposed to water, turning into a sticky paste that clogs drains. A small amount may not cause immediate damage, but repeated use can buildup over time.

Better option: Dispose of starchy leftovers in the trash or compost.

5. Fibrous Vegetables (Celery, Corn Husks, Banana Peels)

Fibrous foods act like string...the long strands can wrap around the disposal’s moving parts, causing jams or motor strain.

Common offenders include:

• Celery

• Corn husks

• Banana peels

6. Bones

Garbage disposals are not designed to grind hard materials like beef, pork, or poultry bones. These can damage internal components or burn out the motor. Even if the disposal doesn’t break immediately, bones can dull performance over time.

7. Shellfish Shells

Lobster, crab, shrimp, and clam shells are hard and sharp, making them difficult for disposals to break down properly. They can jam the mechanism or damage internal parts.

8. Onion Skins

The thin, papery membrane in onion skins can wrap around disposal components and contribute to clogs, similar to eggshell membranes.

9. Paint or Chemicals

These substances can damage your disposal and contaminate water systems. Always dispose of paint and chemicals through appropriate hazardous waste programs.

10. Non-Food Items (Paper Towels, Plastic, etc.)

Garbage disposals are designed for small food scraps, not trash. Non-food items don’t break down and can cause jams or blockages.

Bonus Tip: Garbage Disposals Aren’t Designed for Full Plate Cleanup

Garbage disposals are meant to handle small scraps—not act as a substitute for the trash can. Overloading the system increases wear and tear and raises the risk of clogs.

A simple habit that makes a huge difference: Scrape plates into the trash first. Use the disposal only for small residual scraps.

Best Practices to Keep Your Garbage Disposal Running Smoothly

• Always run cold water during and after use

• Feed waste gradually, not all at once

• Avoid grease and fibrous materials

• Clean periodically with ice cubes and citrus peels

These small habits can extend the life of your disposal by years.

Final Thoughts

Your garbage disposal is a helpful kitchen tool, but it isn’t indestructible. Avoiding just a few common mistakes, especially the eggshell myth, can help you prevent costly plumbing repairs and keep your home in excellent condition.

If you ever have questions about preparing your home for sale or maintaining its value, I’m always happy to help!