15 Things To Never Put Down A Disposal

Are you putting everything and anything into your kitchen disposal? Garbage disposals are one of the great kitchen appliances to dispose of food waste if you are on city sewer. However, there are times, that even this equipment can stop working creating a needed appliance repair. Local appliance repair services will charge a service call just to evaluate the situation, but you may end up having to call the local plumber to deal with a blockage.

Coffee Grounds

Coffee Ground-Don't put down the disposalLet’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! You should never, ever pour this stuff down the drain, either.


Pasta swells-don't put down disposalAnyone who’s made spaghetti or mac’n’cheese knows that pasta expands when soaked in water. Given that, you can see why you might not want to drop lots of pasta into your disposal and drain where it will, after all, soak in water and keep expanding.

Like most of the products 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 must run 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.


Garbage disposals are wonderful at grinding up and disposing of food waste. But just because they can grind they simply aren’t built to deal with extremely hard items, such as bones.

If you do drop a chicken wing or fish bone 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.


Much like pasta, oatmeal is another expansion threat. Uncooked oats, in particular, will likely slip through the disposal untouched, only to collect and expand down-line. If you’re lucky, they’ll eventually flow out to the sewer.


Ground Up Nuts will stick to your plumbing pipesIf you ever find yourself about to dump several handfuls of peanuts down your garbage disposal, take a moment to consider how peanut butter is produced: Handfuls of peanuts are dumped into a grinder, where they’re spun and mashed into a sticky, thick paste. And your garbage disposal is a fantastic appliance-sized version of a nut grinder. Limit the quantity of peanuts (and other varieties of nuts) that drop in the disposal and you’ll be far better off.

Onion Skins

Onion Skins are bad for disposals and plumbingChopped, 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 catches more items and holds them in place.

Luckily, it’s quite 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 plumbing service.

Egg Shells

You may have heard that it’s a good idea to drop egg shells 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?

No eggshells in the disposalWhile 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).


OK, 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.

Pumpkin and Fibrous Vegetables

If you’ve ever scooped out a pumpkin for Halloween, you know how the long strands can get caught on your hand and scooper, turning the whole situation into a sticky mess. Avoid transferring that mess into your disposal by disposing of pumpkin guts in the trash.

The same goes for veggies like celery and rhubarb. Throw long, stringy stalks straight in the trash to keep the fibers from causing a problem, but don’t worry about small pieces. When chopped up, the fibers are small enough to not create a problem.

Potato Peels

Potato peels are slender enough to slip past the disposal,if peeled with a peeler, potentially catching in the drain. There they can cause the same condition 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 require several potatoes, and the pile of peels quickly adds up.


hard pits not good for the disposal and plumbing pipesPeaches are delicious, and avocados inspired an entire generation of kitchen color schemes, but they both have incredibly hard, dense pits in their center. As a good rule of thumb, if you can’t slice it with a knife, it’s not going to grind up in the disposal. (Actually, it might once or twice, but it won’t be long before you’re taking a trip to buy a new disposal.)

In the event that you do make a habit of dropping too-hard items in the disposal, it normally won’t destroy the motor, but you’ll end up with a machine that isn’t disposing of waste material properly. Eventually, you’ll just grow irritated with it and end up replacing the unit.

House cleaning Products

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 abnormal 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 separate any grease build-ups. (Make sure you never, ever put these items in your dryer.)


This really 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 stiffen into an intractable blockage. Yet again, just a little paint heavily diluted will not be a problem so long as it’s greatly diluted. But brushes and rollers should be washed with some forethought, using a proper container, while bulk paint should be discarded properly.

Corn Husks

husk your corn and put in trashHusking corn creates a significant amount of waste products, and whenever you can may go in the compost pile or garbage, as opposed to the garbage disposal. The strong, fibrous husk and fine strings of corn silk make a dual hazard for disposals.

So whether your corn is store-bought or homegrown in a garden, it’s wise to husk directly into a bag, and never allow it to go nearby the garbage disposal in any way.


Really tough shells from sea food such as crab, lobster, shrimp, and oysters are a frequent garbage disposal problem. Several shells are much too thick to smash up properly, even though the ones that may slide through (like shrimp) have an opportunity to locate in the drain. So skip the garbage disposal and drop the shells in the garbage, preferably a little trash bag to enable you to take it from the kitchen immediately.

I hope this was helpful, and you’ll adjust what you put down your disposal and save yourselves future headaches!