10 things you should never put in your garbage disposal

I’ll never forget the Thanksgiving our garbage disposal backed up. After enjoying a leisurely holiday dinner in the dining room, we returned to the kitchen to discover a sink brimming with what looked like vomit. The garbage disposal had clogged, sending bits of food back up and out the drain, filling the sink.

This sight and the resulting cleanup job is something I don’t wish upon anyone. And thankfully, with proper usage and care, a garbage disposal shouldn't usually require regular maintenance from a plumbing professional, says Don Glovan, franchise consultant with Mr. Rooter Plumbing.

To make sure things keep running smoothly, it’s important to avoid putting anything in your garbage disposal that will prevent the unit’s blades from working effectively, adds Doyle James, president of Mr. Rooter Plumbing. The following items can cause your drain to clog.

1. Grease

Grease, oils, and other fatty substances spread a film over the blades of your disposal, rendering them less effective, says James. As time passes, those fats will clog your drain and begin to decay, causing an unpleasant smell.

2. Rice and pasta

When you cook certain foods in water, such as pasta and rice, they expand. “These foods can continue to expand in your garbage disposal every time they come into contact with water,” says James. “If this happens, they can clog your drain or block your disposal’s trap.”

3. Coffee grounds

“When you dump grounds into your unit, they typically fall below its shredders without harm,” says James. But—and this is a big but—coffee grounds eventually form a sludge that can clog your drain over time.

4. Fibrous vegetables

The strings in fibrous vegetables can wrap around blades, inhibiting the machine’s ability to pulverize food waste, says James. To prevent this, toss fibrous vegetables, like celery or asparagus, into a compost pile or the trash instead.

5. Bones

“While some people think that certain bones, such as small fish or chicken bones, will clean a garbage disposal’s walls when they’re being ground up, it’s generally not advisable,” says James. “Most will simply spin in the unit until they slip past the blades and clog your drain.”

6. Non-food materials

A garbage disposal is supposed to grind food waste, not man-made materials, says James. If you wouldn’t eat it, you shouldn’t put it in your garbage disposal. Some things—glass, plastic, and metal—are more obvious, but other small items—matches or toothpicks—also fall into this category.

7. Lemons

Though tossing a lemon wedge in your garbage disposal is often touted as a DIY cleaner, it’s not a good idea, according to the experts at Bill Howe Plumbing. Though the garbage disposal will chop the citrus into small pieces, leaving a fresh scent behind, those pieces can eventually clog your system. Citrus juice is a better solution, but one that should still be done with care—the citric acid can eventually corrode your disposal’s metal parts.

8. Vegetable peels

Peels from fruits and vegetables—potatoes, onions, carrots, apples… you name it—are thin and sticky. And according to the experts at C&W Plumbing, they can get stuck on the sides of your disposal or your pipes, eventually causing a backup.

9. Egg shells

Though eggshells may seem delicate enough, according to Boulden Brothers Plumbing the inner membrane can get caught in the disposal’s blades and the shell can grinds into a sand-like paste that gets stuck in the trap.

10. Pits and nuts

Anything hard and solid—specifically fruit pits and nuts—do not get shredded, says Greg Shepard, owner of Dallas Maids. Instead, they continually hit the blades, eventually dulling them.

Now, to keep your garbage disposal clean

To keep your garbage disposal in working order, run your tap with cold water for a few seconds before and after disposing of solid food, says Glovan. He also suggests cleaning your garbage disposal once per month with an all-natural baking soda and vinegar solution to remove buildup and bacteria.

What you’ll need:

• ½ cup baking soda
• ½ cup vinegar

Instructions:

• Mix baking soda and vinegar.
• Add mixture to the disposal while turned off. Let sit.
• When foaming stops, rinse and drain with water.