For those of us who have garbage disposals, it may seem at times that we have nearly unlimited freedom to throw things down the sink, turn the disposal on, and not worry about it. However, while garbage disposals are certainly powerful tools, they also have their limits. On top of that, some makes and models of disposals are simply more powerful than others. Not to mention the age and condition of your current disposal affects its ability to properly do its job.

As Nashville’s plumbing services company of choice, we’ve seen countless issues with garbage disposals. One of the most common is people simply being unaware of what types of items garbage disposals can and can’t handle. Today we’ll be going over five items you should never be throwing into your disposal.

Egg Shells

While egg shells certainly seem like they’re safe to throw into the sink, there’s actually more to an egg shell than you might initially think. While the shell itself is certainly no problem (it cracks and breaks down easy enough), it’s the membrane that lies just inside the shell that can cause a problem in your pipes. Once in your pipes, they can attach to the walls and act as a type of glue for food particles that come through, wreaking havoc over time.

Potato Peels

Starchy vegetables, particularly potatoes, have the potential of creating a soupy mess in your disposal. Over time, the high amount of starch in the potatoes can clump up and form a thick paste, clogging your disposal. The peels themselves might also pass through the disposal and get stuck in the pipes, creating a clog that’s particularly difficult to remove. 


Unless you have an extremely powerful disposal, bones will simply get caught in the disposal and refuse to break down. Bones will continue to spin around the blades and get nowhere. Even if it does break down, they’ll have a very difficult time making their way through the pipes. It’s best just to completely avoid throwing these down.


This one is actually surprising to many people. Celery seems hard and sturdy enough. After all, it provides a satisfying crunch when you eat it. However, the issue with celery lies in its fibrous strings. These can get tangled around the disposal’s blade and really hinder movement.

Coffee Grounds

Ah, coffee grounds. This delicious morning pick-me-up is the cause of untold amounts of drain miseries. Coffee grounds may appear to easily wash down the sink, but they can actually pile up and create a sludgy mess in your drain.