11 Things You Should Never Put Down a Garbage Disposal

If you have a fully operational garbage disposal in your kitchen sink, you’re likely in one of two groups. The first is comprised of conscientious individuals who know exactly what they should and should not toss down to prevent those blades from grinding to a halt.

The second group is comprised of individuals who simply refuse to use their garbage disposals, so fearful they are of causing them to jam or break.

But it’s not just the appliance that you have to worry about offending with your cast-off food and household debris. It’s more about what your drain pipes can handle.

We discussed the matter with a few professional plumbers, all of whom have received their fair share of panicked phone calls about garbage disposals.

Garbage

Perhaps the appliance is overdue for a name change; Roy Barnes, Co-owner of Service Force Plumbing, says you shouldn’t use your garbage disposal to get rid of garbage.

“It’s not good for your home’s drain pipes, and it’s actually not great for your city or town’s sewer pipes and wastewater treatment efforts, either,” he says.

Don’t assume just because something looks like it will eventually break down that your garbage disposal is up to the task.

Justin Cornforth, CEO of Ace Plumbing, says, “Paper towels, plastic from packages and wrappers, broken glass, parts of rubber gloves, sponges, cigarette butts, and even dental floss and hair can cause breakage.”

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Grease, Fats, and Oils

You might already know that this slick trio should never be poured down a regular drain if you want to avoid plumbing problems. But grease especially should be a hard pass for your garbage disposal. 

“[Grease] may look harmless when it’s a warm liquid you can run through your disposal, but it will cool quickly in a dark, hidden pipe and become a sticky mess that can either create a blockage on its own or grab other debris as it passes through,” says Hendrick Vandepoll, Master Plumber and Co-owner of Service Force Plumbing.

Grease and fats should instead be cooled and then dumped in the trash. Even thinner oils should be kept out of the drain; otherwise, they’ll coat the inside of the pipes and make them sticky, he says.

Bones, Fruit Pits, Nuts, Eggshells, Coffee Grounds, etc.

Even if your garbage disposal is marketed as being able to cut through hard food scraps, many pros would argue that if you can’t slice through it with a knife, don’t allow your garbage disposal to attempt it. 

“Don’t use your garbage disposal as a trash can,” says Nate Hudelson, Master Plumber at Schlueter Plumbing. “When you clear those plates, especially from big holiday meals, scrape as much as you can into the trash.”

Eggshells and coffee grounds are also no-nos. Sure, they seem innocuous, but they can still clog up your drain. Go ahead and discard them in your trash can, or better yet, add them to your compost pile, recommends Barnes. 

Even if you have successfully discarded any of these verboten foods, consider the effects on your pipes.

“Your drainpipes are designed to handle fluids and debris from your toilet, dishwasher, and washing machine,” says Barnes. “Don’t ask them to do more than that.”

Starchy Foods

Keep starchy foods out of your garbage disposal’s diet, including rice, pasta, and particularly potatoes.

“Potatoes and potato peels [along with grease] being put down the drain are a big reason that the day after Thanksgiving is one of the busiest plumbing crisis days of the year,” says Barnes.

Hudelson kindly requests that you add instant potatoes and breakfast cereal to the do-not-dump list.

He recalls one service visit where he discovered that the garbage disposal had simply whipped up the potato flakes, resulting in a very difficult drain clog. Then, there was the time a homeowner attempted to pour down two family-sized boxes of Cheerios.

“The mixture became a thick, smelly bread dough that took hours to unclog,” he recalls.

Fibrous Foods

Fiber is good for your body, not your garbage disposal. Cornforth says he and his crew have often found the remains of various vegetables stuck in broken disposals. Offending foods include onions, asparagus, celery, and artichokes, but the full list of fibrous culprits is much longer.

“Over time, if these items are constantly thrown away, they wrap around the blades and motor, causing clogs,” he says. 

If you have committed any of these kitchen crimes and your garbage disposal still whirrs on, kudos to you. But your appliance might be on borrowed time. While Cornforth says a single faux pas likely won’t end in disaster, avoid bad habits in the kitchen. 

“Most often, garbage disposal breakdowns are caused by neglect and regular attempts to dispose of items that should not be thrown away,” Cornforth says. “It is not quite accurate to say that the last bone or coffee grounds caused the breakdown, but they were just the final straw that broke the system.”