Plumbers Say: Never Put These 7 Things Down Your Garbage Disposal

A garbage disposal feels like a magic “make it disappear” button, until your sink backs up and you’re staring at a plumber bill you didn’t budget for. The truth is that disposals are built to handle small scraps, not act like a trash can or a compost bin. Some foods gum up the blades, some expand and clog pipes, and some create greasy sludge that sticks to everything. The best money move is preventing the problem in the first place, because drain issues rarely stay cheap. Here are seven common items plumbers warn against, plus what to do instead.

1. Grease, Oil, And Fat

Pouring grease down the drain seems harmless when it’s hot and liquid. As it cools, it turns into a sticky coating that traps other debris and narrows your pipes. Even if your garbage disposal grinds well, the grease moves down the line and creates a clog you can’t see. Wipe greasy pans with a paper towel and toss it, or pour cooled grease into a sealed container and throw it away. This one habit can prevent the most expensive kitchen backups.

2. Fibrous Vegetables Like Celery And Corn Husks

Stringy foods wrap around the disposal’s components and can jam the system. They also tend to slip through in long strands that tangle and collect in bends of the plumbing. If you’ve ever pulled a wad of wet fibers from a drain, you know how gross and stubborn it can be. Compost these scraps or toss them in the trash instead of feeding them to the grinder. If you want to rinse peels or tiny bits, do it with lots of running water and keep the amounts small.

3. Starchy Foods Like Pasta, Rice, And Potatoes

Starches are sneaky because they don’t look dangerous when they go down. Once wet, they swell, break down into paste, and stick to the sides of your pipes. Even a small amount can combine with other debris and create a thick clog. When plumbers say the garbage disposal isn’t a food processor, this is a big reason why. Scrape starches into the trash, and if you must rinse a bowl, rinse it into a strainer first.

4. Eggshells And Coffee Grounds

Eggshells don’t sharpen blades, despite the myth, and the membrane can catch and contribute to buildup. Coffee grounds clump together and settle like wet sand, especially in older plumbing. A garbage disposal may grind them, but the problem often shows up farther down the pipe. Toss eggshells and coffee grounds in the trash or compost them, where they’re actually useful. If you love a fresh-smelling sink, use citrus peels occasionally, but keep it minimal and run plenty of water.

5. Bones, Pits, And Hard Shells

Hard items can crack internal components or dull the grinding ring faster than you’d expect. Even if the disposal is powerful, grinding bones creates dense particles that can settle and contribute to blockages. Fruit pits, nut shells, and shellfish shells are also common culprits because they’re tough and irregular. Put these in the trash and save your disposal for soft scraps only. If you hear loud rattling or grinding, shut it off immediately and check for hard objects.

6. “Flushable” Wipes, Paper Towels, And Stringy Nonfood Items

This is a big one because it’s easy to treat the sink as a catchall. Paper towels don’t break down like toilet paper, and wipes often don’t break down the way the label implies. Anything stringy, like dental floss, twist ties, or produce stickers, can tangle and jam the mechanism. A garbage disposal isn’t designed to handle non-food materials, and your plumbing definitely isn’t either. Keep a small trash can near the sink so you’re not tempted to rinse things away.

7. Garbage Disposal Mistakes With Chemical Drain Cleaners

When a clog happens, people often reach for harsh drain chemicals first. Those products can damage pipes, harm septic systems, and create safety risks if a plumber needs to work on the line later. They can also splash back if you’re running the disposal and water at the same time. Start with safer options like a plunger, a drain snake, or removing and cleaning the P-trap if you’re comfortable doing that. If the clog keeps returning, call a professional before the problem becomes a bigger repair.

The Simple Sink Routine That Prevents Expensive Clogs

Treat your disposal like a helper for tiny leftovers, not a replacement for the trash. Scrape plates into the bin, compost what you can, and run cold water before, during, and after using the disposal. Feed small amounts at a time instead of dumping a full bowl of scraps down all at once. Clean the splash guard and drain opening regularly so buildup doesn’t start. A few small habits can keep your kitchen running smoothly and protect your wallet.

What’s the one item you used to put in your sink that you’re going to stop sending down the drain?

What to Read Next…

Home Insurance Companies Are Re‑Categorizing Common Damages

7 Times People Accidentally Void Their Home Warranty

Certain Winter Repairs Are No Longer Covered Under Older Home Warranties

Top HVAC Mistakes That Cost Homeowners Energy and Money

6 Early Warning Signs of Water Damage Every Homeowner Should Watch Out For

Catherine Reed

Catherine is a tech-savvy writer who has focused on the personal finance space for more than eight years. She has a Bachelor’s in Information Technology and enjoys showcasing how tech can simplify everyday personal finance tasks like budgeting, spending tracking, and planning for the future. Additionally, she’s explored the ins and outs of the world of side hustles and loves to share what she’s learned along the way. When she’s not working, you can find her relaxing at home in the Pacific Northwest with her two cats or enjoying a cup of coffee at her neighborhood cafe.