Most homes built by a standard home builder have come fitted with a sink disposal unit. They generally last somewhere between 5 and 10 years under heavy use. However, this is under optimum use conditions. If a user is putting things down the drain that don’t belong there in the first place, it will definitely damage the disposal and require garbage disposal services for repair. Here’s a list of 8 things one should never put in their sink disposal:

Coffee Grounds

They might seem to be small enough for a disposal to make short work of them, however, coffee grounds will do a number on the kitchen plumbing after the disposal and deep in the waste line. Grounds have a bad habit of sludging up. The disposal will make them smaller, but once past the machinations, the material will consolidate again later in the drainpipe. The best approach is to avoid the sink altogether and either throw them in the trash or, better, use grounds for soil composting in a garden.

Potato Peelings

While peelings seem to make sense in a disposal being vegetable matter, when processed in the disposal they actually turn into a gooey muck that sticks to everything. That slime deposits after the disposal blades and in the exit pipe. Once clogged, it will resist water and back up the entire sink. A user will quickly face a muddy swirling pool of wastewater going nowhere but back up the sink itself.

Heavy Fiber Vegetables

Along with potatoes, and vegetables that are heavy the fibrous scale won’t process very well either. The list is crowded here with everything from kale to pumpkin, chard, and celery. While the material will shred, the fibers in the material tie up in the blades and, with enough of them, the blades stop being able to spin and do their work. Another common problem along the same lines is the label stickers on the same vegetables too. All of this should be put in the trash instead or, at least for the vegetables, composted.

Grease, Fat, and Lard

Just about two-thirds of what people cook involves some kind of fat, grease, lard, oil, or similar. Add in butter, meat cook-off, and more, and the amount of water-resistant material will create all sorts of plumbing problems. Pouring them down the disposal won’t cause the machine much harm, but the drain pipes will easily clog with the same. Oftentimes, hot water is used to clear this issue, but it really just moves the grease and fat further down the line. Avoiding the drain altogether and pouring old cooking grease and fat in the trash is a smarter idea.


Having long been a traditional type of food thrown down the disposal, generations have been taught they are okay to shred. While the shells themselves are not a problem, the egg membrane within the egg is another story. The issue is that the membrane is flexible and stretchable. And that means it can end up wrapping around blades versus being cut and shredded by them.

Enough material, such as what’s produced in a big baking project on a regular basis, and the disposal’s life will be cut short. Onion skins produce a similar problem as well. Again, both can be put to good use in compost piles instead.

Paint of Any Kind

Probably the most attractive solution for getting rid of water-based paints, especially children’s paint, disposal, and sink can seem the perfect solution. Don’t do this. Even if water-based, all that chemical simply goes back into the water system, contaminating drain water and recycled water. Additionally, the paint will stick to the inside of the plumbing, eventually contributing to clogging.

Pits, Nuts & Seeds

All three of these items can seem to be perfect for disposal but, combined with water, they actually turn into goo. Think about it, peanut butter is literally oil, peanuts ground up, and ingredients. The same happens to nuts and seeds inside the disposal and drain. While it will process, eventually the mess turns into a clog ball in the entire system. Compost or trash are better solutions.

Small bones or Shells

Both made of organic calcium, shells, and small bones are oftentimes thrown in the disposal with loud effect. While garbage disposals are most times assumed powerful enough to do the job, the blades do take a beating. Low-end disposals see their life shortened with regular work like this, and even high-quality disposals don’t last as long as expected. All of this can be avoided by simply putting all the bone and shell material in the trash.

A disposal is a great tool for the kitchen, but its use should be targeted. Avoid the above, and it will last a lot longer as well as avoid preventable repairs.