The Google has conflicting answers. I come from a background of "everything goes in the garbage disposal", my wife's background is "never put anything in the garbage disposal". I suspect reality is somewhere between us.

Note: I'm talking about the garbage disposal unit under the sink.

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    From what my home inspector told me, not if you want it to last a long time.
    – justkt
    Commented Nov 29, 2011 at 14:09

14 Answers 14


I've always put egg shells down the disposal. The "official" word from one manufacturer is:

Most forms of food waste can be put through the food waste disposer — bones from fish and poultry, meat, large meat bones, fish scraps, vegetables, fruit, egg shells, and much more. Very stringy or fibrous foods such as celery should be avoided. Food waste disposers are designed for food waste only and packaging materials should not be put into the disposer.

Given that this manufacturer says you can put large bones in a disposer, I can't imagine that eggshells would do any damage.

And as a practical matter, I've seen name-brand disposers at Home Depot for $100, so even if you felt you were shortening the life of your disposer by a small percentage by putting too much into it, it's not a big deal to get a new one.

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    Its one thing to replace a garbage disposal for a mere $100, but if plumbing problems result from putting the wrong stuff down, that can cost a great deal more. That said, I am comfortable putting most small items down. But I avoid bones, vegetable peels, celery, etc. Commented Mar 5, 2011 at 6:48
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    I've never had a problem with "crisp" peels, e.g. apple, carrot, cucumber. My biggest disaster was with a large quantity of spaghetti.
    – user194
    Commented Mar 5, 2011 at 16:15

If you have a septic tank, avoid using the garbage disposal, especially for anything like egg shells, bones, coffee grounds, and other things that the bacteria in the tank won't eat. Worst case scenario is that they can plug up your leach field for a very expensive repair.

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    Generally if you have a septic tank you shouldn't put in a garbage disposal. Usually septic tank houses don't come with one pre-installed.
    – ramblinjan
    Commented Apr 10, 2012 at 18:36

Living in an old house (~100 years) with old plumbing and old pipes, I barely put anything down our drains except liquids. Besides, eggshells are FANTASTIC for your roses and your compost. Why waste them? : )

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    I live in a condo in the city. I've only got two options: sink or dumpster.
    – kubi
    Commented Mar 5, 2011 at 2:56
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    if you rinse them out and let them dry, i am sure someone with a compost pile would take them off your hands. i am just really leery of putting too much down a disposal, to be honest, plus they are so good for soil that it just seems silly to me to waste them that way. if you must, i would think grinding them up in a disposal would be ok.
    – franko
    Commented Mar 5, 2011 at 2:59

We live in a major metropolitan area, and I recently replaced our garbage disposer. While it was off I took a look at the pipes under the sink and they were just caked with black rotting gunk inside them. I replaced them with new ones, and since then our cockroach problem seems to have gone away completely. I believe all that rotting crud inside the pipes was a full time food source for the bugs. Used to be if you turned on the kitchen lights at 2am you would see a scurry of activity on the counters. Apparently, now that the food source is gone, they left. Turn on the lights at 2am these days and there are exactly ZERO roaches.

Now we use the disposer for cleaning the scraps off the plates, but that's about it. If there's a large quantity of something that needs to be thrown away, we'll put it in a two Walmart bags and store it in the freezer till trash day.


Most garbage disposals can handle just about anything you put down them, up to and including pieces of bone. The problem is the drain pipe: if you have a long, gently-sloped drain that the material is going through then heavy, granular material (e.g. ground eggshells) will settle to the bottom and accumulate. Dry onion peels can also accumulate, especially when there's grease in the pipe.

I've had both eggshell-based and onion-peel-based clogs in my kitchen drain (which goes 18' across the house without a whole lot of slope). So now I never run either down the disposal.


I had never had a problem with our disposal until today... the day my wife put eggshells in there. There could probably have been other contributing factors.

I have read multiple debates and the controversy is enough to get me to discontinue the practice. Garbage, compost, chickens, or a giant laser, all seem like better options to me!


We give our egg shells back to our chickens. They need the chalk for new eggs and they like it. But I think this isn't really an option for you, unless you sometimes feed the birds in the park or something.

You can eat the egg shell yourself, it's quite healthy (if I can believe the internet).

You can put them in the compost container, but I wouldn't put them in the septic tank. Just throw them away in the garbage.

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    Another use for egg shells is when brewing coffee -- my dad would put an egg shell in with the coffee grounds; the internet claims it's a pH thing, to counter acidity.
    – Joe
    Commented Mar 6, 2011 at 4:37
  • @Joe: I didn't know that. And does it affect the taste? Or why does your dad do it?
    – Mien
    Commented Mar 6, 2011 at 21:56
  • he said it made a difference; others on the internet know about it, but none really seem to know why it's done. I personally don't like coffee, so I've never done a taste test to compare. (and then he'd put both the shells and coffee into the compost pile afterwards)
    – Joe
    Commented Mar 7, 2011 at 0:01

Biggest no-nos are starches, fats, (Thanksgiving is a plumbers busiest day), proteins, and fibrous vegetables. I live in a city highrise. I do put some egg shells and coffee grinds occasionally. What I do weekly, is put 1/2 cup of baking soda and 1 cup of white vinegar in the drains (disposal and other kitchen drain). Let stand for 1/2 hour or so and follow with very hot water. This is good practice. Also helpful are white vinegar ice cubes. They clean the blades.

I would not put said refuse in a septic system for the same reasons as others gave.

  • Don't starches, fats and proteins pretty much cover everything? Commented Sep 20, 2016 at 18:08
  • @PoloHoleSet - no, that's why he had to add fibrous vegetables to the list. I think with that addition, it does cover pretty much everything.
    – Megha
    Commented Jul 25, 2017 at 5:32
  • @Megha - I probably have to turn off the "science" part of my brain that's so pedantic about exact language, and look at things more from the common, everyday and practical use perspective. For instance, a chain of starches is no longer considered a starch, because it can't be digested and broken down like a basic starch can, which is where I went wrong here. Thanks! Commented Jul 25, 2017 at 14:02

I was always taught the egg shells were good for the pipes, but when our drain clogged, the trap was filled with coffee grounds and egg shells. Perhaps the egg shells would normally be fine, and they only got stuck because of the coffee grounds (which I know should not go down--our guests did not). Even still, after that experience, I now have a policy against egg shells (and coffee grounds) in the disposal.


Many years ago my mom had clogged kitchen pipes; after the plumber cleaned it all out, he advised her not to put egg shells, celery or onion skins down the disposal. I didn't know if the disposals had been vastly improved since then, but sounds like items like these are still questionable.


The key to success in putting anything through the disposal is to avoid putting too much in at one time and don't skimp on running water to flush it down. In that way you can even put eggshells, coffee grounds, and vegetables down your disposal. If you have a lot of leafy or fibrous vegetables to put down, or shrimp shells, you can do it but you end up wasting a lot of time and water; better to just put that much stuff in the trash, or better the compost heap if you have one.

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    In the case of shrimp shells and veggies, freeze them and use them for stock making!
    – Preston
    Commented May 27, 2014 at 6:46

I found on manufacturers site http://www.insinkerator.com/en-us/Household-Products/Garbage-Disposers/Pages/Disposer-Dos-and-Donts.aspx and http://garbagedisposalexpert.com/insinkerator-comparison/ that, for some models, says “Stop worrying about what food you can or can’t put in your disposer”. So, depending on the model

  • I wouldn't trust that at all. It's easy for the disposal manufacturer to say their systems let you put anything down the drain, but that DIRECTLY contradicts what I read from companies that inspect and pump septic systems. Insinkerator even sells a model that claims to help your septic system by injecting beneficial bacteria every time you use it. But other experts say that adding the bacteria is a waste of money and can actually destroy the anaerobic bacteria needed in your system!
    – S2inVT
    Commented Jan 2, 2021 at 15:14

Well since I live in a city with a sewer system I pretty much run everything through my garbage disposal. I replaced the 25 year old original with a new KitchenAid and the guy told me I could run just about whatever I wanted through it. I avoid bones and extremely hard substances but egg shells, peels, left over food, it all goes down and gets turned into paste before being washed down into the city sewer system. So I would say it depends on your disposal and the condition of your pipes. If my pipes were older I would probably be more careful about what I put down the drain.


Growing up my grandma told me that egg shells were good for the garbage disposal. They sharpen the blades. I wouldn't put potato peeling or coffee grounds in it

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    Ma told me the same thing. Nowdays she won't let eggshells near a disposal. Commented May 25, 2014 at 19:24
  • Yeah, that was an old grannies' tale. I just read that the membranes inside the shells can bind up in the disposal, not helping at all.
    – S2inVT
    Commented Jan 2, 2021 at 15:15

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