Let's not discuss the economics of this - the fact is that it sometimes does happen.

I don't think food is physically that different from "poop" (especially certain types of it)

  • 1
    It's fine if you use a Humanure composting toilet.
    – Jay Bazuzi
    Commented Aug 31, 2011 at 2:40
  • 6
    Are you on a public sewer system, or a septic system? Flushing whole foods into a septic system can cause serious problems or complete leach field failure. Beware! Commented Sep 2, 2011 at 10:23
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    FWIW, uneaten food is very different from poop. Poop is mostly water and dead bacteria, plus a little fiber and some other minor undigested bits. Decently healthy food is mostly complex carbohydrates, fats, and proteins, all of which are much less soluble, so they are much more likely to stick, clump, and clog in your system when they reach corners and build-up along the pipes. Commented Sep 6, 2011 at 23:19
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    I'm puzzled: why on earth would you want to flush food down the drain, any drain? What's wrong with putting it in the trash? (Or in the compost bin if you have one?) The disposer's purpose is so you don't have to sit there fishing grody food waste out of your sink after washing the dishes, not to act as a waste receptacle.
    – Martha
    Commented May 4, 2012 at 1:53
  • 1
    Only if it's a whole pineapple. Commented Feb 11, 2018 at 3:30

5 Answers 5


Depends on the type of food.

Just because it will "go down," that doesn't necessarily mean that it's ok to flush it. Grease is a rather popular example.

Unfortunately I don't know that anyone has compiled a list of all foods that will clog your pipes or otherwise damage your plumbing, but here's a start:

  • Oil and butter
  • Mayonnaise and sour cream
  • Cheese
  • Sauces and dips
  • Salad dressing
  • Cake frosting
  • Pie dough
  • Gravy
  • Turkey and chicken pan drippings
  • Fat remaining on plates from BBQ’d steak


Grains also aren't good, as they will expand as they soak up water.

If you want a safe place to dispose of a little extra food, imo, toss it in a bag and make a trip to a convenience store. Toss it in the trash, go in and buy a soda. The food that would've stunk up your trash can is gone, your toilet isn't clogged, the convenience store guy is happy to have your business, and you're drinking a soda. Life is good. :sunglasses:

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    How is it that different from a sink drain, a disposal drain, or dish washer drain (aside from possibly size, and amount)? Lots of the things on this list would find their way to the sewer via the kitchen sink, why is it that the toilet is so special?
    – Tester101
    Commented Aug 31, 2011 at 12:05
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    You shouldn't put these things down the kitchen sink either, or anywhere in the drainage system. I put them in an old coffee container, then toss it in the trash. Or, I just dump the stuff onto a paper towel, then toss that out.
    – brandeded
    Commented Aug 31, 2011 at 12:51
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    @mbrownnyc: Of course you are not going to drain the deep fryer down the drain, but I imagine small amounts of all of these things are rinsed down the drain on a daily basis in many homes.
    – Tester101
    Commented Aug 31, 2011 at 15:32
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    they are... but when they "get cold," they harden. By "get cold" I mean whatever temperature it takes for the organic matter to return to a solid. For instance, fry some bacon, leave the pan hanging out on the stove... return. Solid. Imagine that stuff slathering along the side of metal pipes, and your drain trap. Yummm! Line hardened arteries.
    – brandeded
    Commented Aug 31, 2011 at 19:21
  • I have seen folks that drained bacon grease down the kitchen sink, I was called to replace the disposal unit (I did this) and explained they were ruining there septic system they thought I was nuts, they had to have the tank pumped and the leach field aireated very expensive but cheaper than a new one. The home was only 10 years old and the tank had been pumped and inspected when they purchased the home less than 5 years prior. Pouring grease down the drain fills the tank with solids and in this case got through the baffle and plugged the field. I agree with @michael+.
    – Ed Beal
    Commented May 9, 2018 at 21:04

First of all, you should abstain from flushing down anything that doesn't degrade. In case of food it's anything that has bones - they are mineral and don't degrade and can cling to some ledge in the piping and then stuff will start collecting there and you've clogged pipes in no time.

Then you should abstain from flushing huge pieces of hard food. Anything thicker than about 3/4 the cross-section of piping can collect and lead to clogged piping.

Finally watch out for the list that user Michael provides in his answer - it's quite reasonable and stuff mentioned there can pose mild to serious risk for piping.

Also it is very important to flush thoroughly so that stuff doesn't collect in horizontal piping close to your toilet. If it collects it can start consolidating and attaching to pipe surfaces and this will lead to a clog much later.

That said you should think twice before flushing. Most of the times you can just throw it into trash. The risk of abuse that would lead to a clog is not very high, but real and you won't like the consequences.


It's best not to put anything in the septic tank other than feces or urine, a monthly dose of Rid-X (not meaning to endorse any specific product) is beneficial.

For a public sewage system I'd say it's OK to flush uneaten/expired food into the system- it's not a closed ecosystem as a septic tank is.

BTW: Cigarette butts still have nicotine which was (is still) used as a pesticide- so don't flush those into a septic system either- it kills the necessary bacteria.

  • I did not know about nicotine but the filters do not decompose and have filled many sceptic systems as well as some female hygiene products that state they are safe, red headed white mice bring lots of business to rotorooter.
    – Ed Beal
    Commented May 9, 2018 at 21:08

Many municipalities are now offering compost collection service (in Hamilton, ON we have a 1 trash bag/week limit, composting is a major part of our waste diversion). This is really the best answer for spoiled/waste food. If your municipality doesn't offer it, you can consider your own composter.

With that said, Sharptooth's answer covered it well. From a waste treatment point of view I think you're ok, but try to avoid overly solid objects (see this for an idea why). From a pipe safety point of view, Michael's answer is pretty good, but I don't encourage making your trash problems someone else's.


Meh; done it for years and it hasn't clogged my toilet up yet. Obviously use some sense with what you're flushing: don't flush a chicken leg down and expect it to not clog, and I don't advise it on a sewer tank, but anything non solid should be fine.

I've flushed old spaghetti meat sauce just recently and if you have a garbage disposal unit it's just slicing your food up before it goes down the drain so there won't be an issue of build up. Because of the frequency of times you flush water and toilet paper to the times you flush food it would rinse it out eventually.

  • Hello, and welcome to Stack Exchange. There may be useful info here but it's tough to figure out with the lack of formatting. I'll edit it, but you might want to put a bit of work into your next answer. Commented May 10, 2018 at 1:41

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