5 worst things to put in a garbage disposal

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The five worst things that you can put on your garbage disposal include grainy and starchy materials, hard materials, fibrous materials, non-food materials, and grease.

Waste disposal

What can clog garbage disposal?

Garbage disposals clog because of the different waste materials that the blade cannot grind. In this post, I categorized the waste so you will understand the reason why you must not put them and for you to remember them easily.

The categories include grainy and starchy materials, hard materials, fibrous materials, non-food materials, and grease.

Grainy and starchy materials are hard materials before grinding but become paste-like after it goes into the garbage disposal.

These materials clump up when they get wet and become sticky. In the presence of grease, they stick on the pipe causing clog to the disposal. Sometimes these are soft and grainy in texture.

Hard materials are stone-like materials when it comes to hardness. They are not easy to break. Garbage disposal has a hard time grinding it. The materials require a meat cleaver to break.

Fibrous materials are stringy. They can tangle up inside the unit. This causes the jam and can lead to possible wear out.

Non-food materials are the type of materials that are supposed to be thrown in the trash bin. They have no place in the sink. They are non-biodegradable. The garbage disposal will have a hard time grinding it.

Grease is another type of material that you must not put in your garbage disposal. Grease solidifies that can cause the clog.

You may have noticed this already on your pipes even without the garbage disposal installed.

5 worst things to put in a garbage disposal

Now that we already classified each waste material, let me give you examples for each category. We have five categories but take note of the types of materials for each.

Paste-like materials

As I mentioned earlier, paste-like materials are hard materials before you grind. However, they clump up when you add water. It means that they do not dissolve even you add water. One of the best examples of this is the eggshells.

Eggshells are easy to grind although hard in nature. However, they do not dissolve. When you add water, it clumps up. In the presence of grease, it sticks to the pipes.

But the interesting thing about eggshells is that some garbage disposals, allow you to grind them. However, some brands do not allow it. Check the manual of your appliance to know if you can grind eggshells.

Another paste-like material is the potato peels. They are soft but it becomes paste when you add water.

The starchy content of the potato peels becomes paste-like when you add water. Pasta, rice, and noodles are starchy food that can block the drain pipes. So even they are soft, they can still cause clogs on the disposal.

If you have these food wastes, remove them in your sink and throw them away in your trash bin.

Coffee grounds are tiny grainy materials. However, it does not dissolve in water. It clumps up when you add a liquid.

Similar to eggshells it can stick to the pipes in the presence of grease and can block the pipes.

Hard materials

Hard materials require you an extra effort to break them just like a piece of wood. When you add these materials inside the unit, the blades will have a hard time grinding them.

Fruit pits of cherry, peach, nectarine and avocado are considered hard materials. Never grind it using a garbage disposal. It breaks or dents the blades of your garbage disposal. Seeds are also not allowed. They clog the sink.

Seashells are tough materials. They can weaken the blade and they clog when they get pulverized. Do not put clamshells and other shells such as oysters and lobster.

Do not put nuts inside the unit as well because they become nut butter paste. They are sticky and a bit paste-like. Do you imagine the peanut butter?

That’s how they look like inside the garbage disposal. Nuts can clog the machine.

Bones are hard materials too. Bones from meat can break the blades. But bones from fish can be manageable. Avoid putting the hard bones inside the unit.

Fresh corn on black background

Fibrous materials

Fibrous materials can be problematic as it balls up causing a clog. These materials include corn husks, banana peels, celery, asparagus, and artichokes.

Some premium models of a garbage disposal can handle the fibrous vegetables in small amounts. Refer to your manual if it says so.

Onions can miss the grinding plate. So what happens is that it wraps around the plate. Because it is not ground properly, it can trap other items you put inside the unit, causing it to clog.

Non-food materials

Non-food items must go to the bin. It includes paper towels, stickers, cigarette butts, broken glass, plastic wrappers, and plastic utensils. Always remember that a garbage disposal is not a trash bin.

It is created to get rid of food waste without using garbage bags. It is also created to break the food waste into small pieces so it can smoothly pass the plumbing system.

It does not have the capability to grind materials that are supposed to be ground in a recycling facility.

As a rule of thumb, do not put non-biodegradable materials into the garbage disposal.

Fats and Grease

Never dispose of your butter and oil at the garbage disposal. Instead, wipe your bowl with a paper towel until you do not feel any grease.

However, there are some vegetables that go into the disposal with butter and oil.

In this case, using cold water is helpful. It solidifies the small amount of grease that can be broken by the blades. This technique can reduce the chances of a clog.

Meat trimmings and bacon can dull the blades over time that it can be less effective in grinding.

It is greasy but the main problem with meat trimmings and bacon is that they are hard to break down. They congest the unit that it may stop working.

What’s the worst thing to put down a garbage disposal?

With the list I mentioned, you probably want to know what is the worst thing you can put in the garbage disposal that will stop working.

The top on our list is non-biodegradable waste. Garbage disposal is not designed to be a trash bin where you put everything.

Garbage disposal has another function which is grinding. If the disposal has a hard time grinding the non-biodegradable waste, it can clog and end up overheating.

But if I may add up to the list, it is the grease. Even without the garbage disposal, grease clogs the pipe. When it happens water back up and even a plunger cannot fix it.

The solution for this problem is to remove the pipe and scrape all the grease trapped on the pipe. If it happens to your garbage disposal, you may need to do the same. It is a tedious task that no homeowner wants to do.

I have not mentioned this yet but never use a harsh chemical when you run the garbage disposal.

It can corrode the pipes of your plumbing system that can affect the performance of the garbage disposal. Never use bleach and chlorine. Instead, use cold water to drain the food waste.


Garbage disposal is helpful equipment to ensure your plumbing system stays in good condition.

Clogs are definitely the problem when the plumbing does not work. It can affect not only your kitchen sink but the entire area in your house connected to the plumbing system.

Keeping it in good condition by not throwing any waste material that can cause clogging may help to keep it longer. Do not be lazy in separating the waste if you want the garbage disposal to last long.