8 Things That Should Never (Ever) Go Down Your Garbage Disposal

Coffee Grounds

It’s tempting to rinse coffee grounds away, especially if you're brewing daily. But they clump together like wet sand and settle in the drain, leading to stubborn blockages over time. Instead, sprinkle spent grounds into your compost bin or repurpose them around your home or garden.

Grease, Oils, and Fats

"Oils and grease are another frequently used item that should never be put down any drain," says Brandon Dolan from Dolan Inc., a plumbing, heating, cooling, and electric company serving central New Jersey since 1949. "Oils and grease do not mix with water and will get trapped on the drain pipe walls. Over time, they'll congeal together and create a very devastating blockage."

As these substances cool, they'll solidify and cling to the insides of your pipes, forming a sludgy, stubborn mess. "Grease especially requires specific drain cleaning equipment in order to clear the blockage inside the piping," warns Dolan. Let cooking oils and fats cool, then pour them into a sealable container and discard.

Starchy Foods

Potato peels, pasta, and rice may seem innocuous, but once exposed to water, their starches swell and turn sticky, leading to gummy clogs in your pipes, says Dolan. "Starchy items should be put directly into the garbage also to avoid clogging inside the body of the disposal," he explains.

Shells and Bones

"Bones and shells of any kind can lodge or break the blades of the garbage disposal, causing damage and clogging," says Dolan. This includes shrimp shells, crab shells, eggshells, chicken bones, and fish spines. They're too hard to break down properly, which can dull the blades or lead to clogs in your pipes. "Broken blades almost always require a replacement, and this type of damage is not covered by warranty," according to Dolan. Compost what you can, and discard the rest thoughtfully.

Fibrous Vegetables

Celery, asparagus, corn husks, and artichoke leaves all have long, stringy fibers that tend to wrap around the disposal’s blades, dulling them or preventing proper rotation. These scraps are better suited for your compost pile where they’ll break down over time.

Fruit Pits and Hard Seeds

Avocado pits, peach stones, and other hard fruit cores are far too tough for your disposal’s blades and can cause serious damage. As a general rule, if you can’t cut it easily with a knife, it doesn’t belong in the disposal.

Non-Food Items (Even the Accidental Ones)

From twist ties to produce stickers, it’s surprisingly easy for small non-food items to sneak into the sink. These don’t break down and can damage or jam your disposal’s internal components, Dolan says. Similarly, paper products like napkins and paper towels are designed to absorb, so they can create serious clogs if put down the disposal. Always do a quick visual sweep of your sink before flipping the switch.

Large Amounts of Food at Once

Even if the food is technically disposal-safe, overloading your unit can cause it to jam. Think of it like a blender—feed scraps in slowly to avoid overwhelming the system. "Make sure you always run the water when using the disposal," Dolan adds. "The metal blades spinning on each other without lubrication can cause serious hazards. It could burn up, damage the motor, or cause electrical shock hazards," he explains.