12 Things You Should Never Put Down Your Garbage Disposal

A garbage disposal is an electronic device fitted to the underside of a kitchen sink. It uses blades to grind food waste into pieces small enough to be carried away in the plumbing system. It is a clean, fast, eco-friendly way to get rid of your kitchen waste, as food goes into the water system and not a landfill.  

While things like vegetables, fruit, cooked foods, and even ice can go down a garbage disposal without problems, other things can clog your plumbing or damage the blades. This can be costly to have repaired, so it’s in your best interest to know how to properly use one. To ensure the long life of your garbage disposal, avoid putting these items down the drain.

1. Coffee Grounds

Maybe you've heard a myth that coffee grounds are good for your plumbing system and keep away bad odors. But actually, they're one of the worst things that you can put down the drain, as they form into a sludgy mess and can block your pipes. Coffee grounds are best disposed of through composting, where their nutrients can be put to use.

2. Potato Peels

Potato peels can create a sticky, gluey mess that causes plumbing blockages. After the peels pass through the blades of your garbage disposal and into pipes, they get waterlogged and break down into a viscous liquid. Small quantities might not do much harm initially, but larger quantities and continuous use can cause trouble. 

3. Fibrous Vegetables

Produce is usually safe to dispose of but certain fibrous veggies, such as celery, rhubarb, pumpkin innards, chard, kale, and asparagus may get tangled up in the blades and cause them to malfunction. Also, remember to take the stickers off the peels of your fruits and veggies before putting them down the disposal. These can stick to the blades or pipes and create blockages too. For potato peels and veggies, the compost heap or organic garbage bin is the most ecological disposal option. 

4. Starchy Foods

Starchy foods like pasta, rice, oats, and beans expand with water. This swelling can cause food to become lodged in a garbage disposal’s blades or kitchen pipes, leading to clogs and preventing proper sink drainage. This could eventually require the repair services of a plumber. The sticky, starchy mixture may also coat the blades of the disposal, making them less effective or causing them to malfunction. Dispose of these items in the garbage.

5. Grease and Fats

Things like oils, butter, poultry skin, and bacon grease might slip down your disposal with ease but these substances solidify and stick in your pipes. Their accumulation can lead to significant plumbing issues such as backups or leaks that can be costly and time-consuming to fix. It’s best to dispose of them in jars or cans in the garbage, or better yet, find a local facility that accepts fats such as cooking oil for recycling.  

6. Onion Skins and Eggs

Some experts say eggshells are relatively safe and may even help garbage disposal blades stay sharp, but the problem is the membrane just beneath the eggshell. It can wrap around the blades, making them operate less efficiently. Onion skins can do the same or slip past the blades intact, forming a clog in your pipes. If this happens and you can see fragments entangled in the blades, turn off the disposal and use tongs or pliers to remove them. Then pour a pot of boiling water down the disposal to loosen the clog. If this has no effect, you may need to use a plunger or plumbing snake to remove the clog. In the worst-case scenario, you will need a plumber. Onions and eggshells are better disposed of as nutrient-rich additions to a compost heap.

7. Paint 

It might seem unlikely that you’d ever willingly put paint down your kitchen sink, but if it’s the closest water source to a kid’s art project or maintenance work site, it might be tempting to wash hands or supplies in a sink with the garbage disposal. However, you should avoid sending paint and harsh chemicals down your drain as they will damage your disposal and the pipes. Oil and latex paints can coat your pipes before hardening and causing blockages. 

8. Nuts

Nut butters are made by grinding nuts into a paste with food processor blades. Now imagine that mess in your pipes. Avoid putting large quantities of nuts down your disposal as they can become lodged in the pipes and cause clogs. Their buildup over time can cause blockages, allowing water to back up, and damage your plumbing system. Untreated clogs can also lead to unpleasant odors and bacteria growth. Throw nuts in the trash or the compost pile instead. 

9. Pits and Seeds

A garbage disposal is designed to handle soft food waste. Peach pits, mango seeds, and other large stones may be too hard on your device. They are very tough and may overwork, bend, or break your blades, or burn out the motor. Avocado and peach pits are also large enough to form clogs. Even smaller pits and seeds, such as cherries and grapes, can cause problems. Fruit pulp or skins should go in the garbage or compost heap. 

10. Shells and Bones 

Shellfish, such as oysters, crabs, lobster, and even shrimp, come with a hard exoskeleton that can be tough on disposal blades and cause damage to pipes. Big bones, such as ribs, are definitely not meant for a garbage disposal and may even break the blades. The jury is still out on small bones. Some experts say this is a no-no, while others say the device is powerful enough to handle them. To avoid any mishaps, toss them in the trash instead.

11. Non-Food Items

It goes without saying that non-food items, such as napkins, paper towels, wrappers, foil, and cellophane, should go in your trash and not your garbage disposal, but sometimes silverware may fall in by accident or a glass may break in the sink. If your disposal is turned on with these items in it, it can lead to clogs or the bending or breaking of its blades. There is also the risk of shards of glass or shattered pieces flying out of the disposal. If attempting to retrieve non-food items, ensure the disposal is fully turned off and pull out the items with tongs or pliers. Depending on placement or the severity of clogging, it might be best to call a plumber to ensure no further damage is done. 

12. Medicine

Since everything ground up by your disposal eventually gets into the water supply, it’s a no-brainer to avoid throwing out medicine with your garbage disposal. Avoid polluting the water supply and dispose of your medicine responsibly. Check the label to see if there are disposal instructions and follow them. Consult a local pharmacy or health center to see if they take back expired or unused medication. If you have no choice but to put them in the garbage, use a resealable plastic bag and mix them up with coffee or animal waste to make them unusable.