14 Things You Should Never Put Down Your Garbage Disposal


That homemade dinner sure was delicious, but let’s face it—there’s nothing fun about the chore that is post-meal clean-up. Before you stuff all the food scraps down the drain and tackle those dirty dishes, remember that there are certain items that you should keep far away from your kitchen sink. But what exactly can you put down your garbage disposal and what items should you simply throw away or compost?

In order to avoid an emergency call to a local plumber like Service Legends, the experts at HomeAdvisor recommend tossing these items in the trash rather than putting them down your garbage disposal. Here are 15 things to never put in your disposal if you want to keep it running smooth and your drains clog-free.

  1. Paint. This is one mistake that DIYers are especially prone to committing. Latex or oil paint should never be poured straight down the drain. It can cling to the side of the disposal or sit in pipes, where it will begin to cure and harden into an intractable clog. Again, a little paint heavily diluted won’t be an issue as long as it’s heavily diluted. But brushes and rollers should be cleaned with some forethought, using an appropriate container, while bulk paint should be disposed of appropriately.
  2. Grease and Oil. Since grease hardens when it cools, it can easily solidify and clog your pipes. Once you’re finished cooking, pour hot grease or oil into an empty milk carton or an unrecyclable takeout container and toss it in the trash once the grease has cooled down and solidified.
  3. Coffee Grounds. Coffee grounds in disposal: Don’t do it. Let’s start by debunking a common folk remedy. While it’s true that dropping coffee grounds into your garbage disposal reduces odors in the short term, it can actually cause more serious problems down the drain. To understand why, think about what used coffee grounds look like when taken out of a filter: They reduce into a dense, thickly packed pasty wad. And that is exactly what you don’t want going in your drain lines! If your disposal is starting to smell, here’s a sneaky way to get it smelling better quickly. Leave the grounds out of your disposal, and use them to keep critters out of your garden instead.
  4. Pits and Seeds. Hard, round objects don’t grind up very well, and even small pits, like those from an olive, can get stuck in your disposal and clog the drain.
  5. Nuts. If you ever find yourself about to dump several handfuls of peanuts down your garbage disposal, take a moment to consider how peanut butter is made: Handfuls of peanuts are dumped into a grinder, where they’re spun and mashed into a sticky, thick paste. And your garbage disposal is an excellent appliance-sized version of a nut grinder. Limit the number of peanuts (and other varieties of nuts) that drop into the disposal and you’ll be far better off. Peanut butter works on sandwiches and in mouse traps, but a disposal lined with peanut butter is a pain to clean out and a potential clog to your drain.
  6. Celery. Yes, you read that right. Despite their good-for-you benefits, stringy, fibrous, or starchy vegetables (asparagus included) can wrap around your disposal’s blade and cause a blockage.
  7. Onion Skins. Chopped, diced, or in chunks, most onion waste shouldn’t be a problem for your disposal. The problem comes with the thin membrane that lies just below the dry, outer-most layer of an onion. That thin, wet layer is often removed before the onion is chopped, and thrown into the disposal. But the layer is so thin that it can pass through the disposal, missing the blades, and wind up wedged in the drain, where it acts as a cargo net on a pickup, catching more items and holding them in place. Luckily, it’s fairly simple to avoid this problem. Just drop the thinnest outer layer in the trash, or cut it up before dropping it in the disposal. It’s a few seconds of work that can save you hours of work or an expensive visit from a plumber.
  8. Potato Peels. Potato peels are thin enough to slip past the disposal, potentially catching in the drain. There they can cause the same issue as the egg membrane, acting like a tiny catcher’s mitt, holding up other waste and creating a clog. Again, a few peel pieces are nothing to worry about, but many recipes call for several potatoes, and the stack of peels quickly adds up.
  9. Rice and Pasta. Because rice and pasta both swell when they’re submerged in water, they can gather in the trap of your disposal and clog it over time. Like most of the items on this list, a few scraps cleaned off of a plate won’t hurt. But don’t try to dispose of an entire pasta casserole, and when you do run the pasta through the disposal, run the water as cold as it will go for 30 seconds afterward, to flush it through the trap and into the mainline.
  10. Oatmeal. Much like pasta, oatmeal is another expansion threat. Uncooked oats in particular are likely to slip through the disposal untouched, only to collect and expand down-line. If you’re lucky, they’ll eventually flow out to the sewer. If you’re not … well, then it might be time to refresh your advanced drain-cleaning skills.
  11. Egg Shells. Can you put eggshells in a garbage disposal? Sure. But should you? No. You may have heard that it’s a good idea to drop eggshells into the garbage disposal. The idea is that the shells somehow sharpen the blades mounted on the disposal wall. It’s hard to say where this theory got started, but if you stop to think about it, when was the last time you’ve seen anyone sharpening knives and lawnmower blades with a carton of eggs? While eggs don’t do much to help your disposal blades, at least the shells themselves don’t do any damage. However, the next time you crack an egg, take a close look at the shell. You’ll see a thin membrane on the inside of the shell that can (like that thin membrane of an onion) get loose and lodge in the drain or around the impeller (the rotor that throws waste against the wall-mounted blades). If you still don’t like the idea of tossing eggshells in the trash, you’ll be happy to hear they can be used in your garden.
  12. Animal Bones. Disposing of animal bones down your disposal is always a bad idea. Bones can easily get stuck, plus they’re significantly cut down on the lifespan of your disposal’s blades. If you do drop a chicken wing or fishbone in the disposal, don’t panic. Disposals are hardy appliances and can handle grinding up the occasional small bone. But if you try to drop a rack of ribs down your sink and grind them up, you’re setting yourself up for disaster.
  13. Trash. Okay, speaking of trash, it’s worth saying this officially: We know it’s called a “garbage” disposal. That doesn’t mean that you should put all your garbage in it. Talk to a plumber or handyman, and you’d be shocked by how many times they need to dig out paper towels, bags, candy wrappers, and banana peels that definitely don’t belong in the disposal. As for all those plumbers who were called out to fix disposals that had been used as trash compactors? Let’s just say that they’ve had a lot of practice replacing garbage disposals.
  14. Cleaning Chemicals. We’re not talking about dish soap or normal cleaners. Those are fine for normal use. The chemicals to avoid are harsh drain busters and industrial-grade cleaners. They can put excessive wear on your disposal and possibly even the drain line. Instead, use ice cubes to clean off the blades, and a little dish soap to deodorize and break up any grease build-ups.

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