Avoid grease, oil, bones, pits, shells, fibrous peels, coffee grounds, starches, eggshells, non-foods, and harsh chemicals in a garbage disposal.
A garbage disposal chews small scraps, not full plates. It grinds soft food into tiny bits that can wash away with lots of cold water. When tough, stringy, or gummy stuff drops in, jams and clogs follow. Repairs cost time and money, and the stink can spread fast. This guide gives a clear, no-nonsense list of what to keep out and what to do instead.
High-Risk Items You Should Not Put Down A Garbage Disposal
Here’s a broad quick scan with reasons and better spots for each item. Cold water or a strong motor won’t fix these troublemakers. Small amounts can still pile up and cause a slow drain later.
| Item | Why It Jams Or Clogs | Better Disposal |
|---|---|---|
| Fats, oils, grease | Coats pipes, cools into waxy clumps that snag other bits | Collect in a jar; toss when full or take to local FOG drop-off |
| Coffee grounds | Settles like sand and forms heavy sludge in traps | Trash or compost |
| Eggshells | Membranes tangle parts; grit accumulates downstream | Trash or compost |
| Fibrous peels (celery, corn husks, onion skins) | Strings wrap around the impeller and stall the motor | Trash or compost |
| Starches (pasta, rice, potatoes) | Swells and turns to glue; lines the pipe like paste | Trash or compost |
| Bones, pits, hard shells | Too hard; they rattle, dull parts, and jam the chamber | Trash |
| Nuts and nut shells | Pulverizes into sticky paste that clings to everything | Trash |
| Citrus peels in bulk | Thick pith sticks to walls; oils don’t help grind | Small slivers only or compost |
| Bread dough, flour, batter | Forms paste that gums up blades and traps | Trash |
| Stringy meats, poultry skin | Rubbery strands twist and bind moving parts | Trash |
| Produce stickers & twist ties | Non-food; collects in traps and at treatment plants | Trash |
| Seafood shells (shrimp, crab, clam) | Hard, jagged edges jam the unit | Trash |
| Pumpkin guts & corn silk | Long fibers knot like rope | Trash or compost |
| Hot fat from pans | Flows as liquid, then solidifies deeper in the line | Wipe pan with paper towel; bin it |
| Harsh chemicals, lye drain cleaners | Corrodes metal parts and can splash caustic fluid | Use mechanical clearing; see safer steps below |
Grease and oil are the worst. Even if hot water seems to carry them away, they cool and congeal deeper in the line. That build-up is a known cause of blockages in sewers. See the EPA guidance on FOG for why even small amounts add up.
Why Grease, Fibers, And Starches Cause So Many Callbacks
Grease And Oil
Animal fat, butter, and cooking oil slide through the chamber, then stick to cooler pipe walls. As the layer thickens, crumbs and coffee latch on. Flow slows, odors rise, and clogs form far from the sink, where snaking is harder.
Fibrous Foods
Celery strings, corn husks, onion skins, and artichoke leaves act like thread. These strands catch on the rotor and rubber baffle. Once wound, the parts grind poorly or stop outright.
Starches And Gels
Pasta, rice, oats, and potato scraps soak up water and swell. Ground bits become paste that lines the trap and branch line. The mix dries like glue between uses, turning a slow drain into a full stop.
Myths: Coffee Grounds And Eggshells
Two tips keep floating around: “grounds scrub the pipes” and “eggshells sharpen blades.” Both fall flat. Grounds settle into dense layers that sit in low spots and traps. Egg membranes tangle moving parts and the grit adds weight in the line. Consumer Reports also warns against tossing chemical drain cleaners into a disposal, since the caustic mix can damage the unit and the sink area.
Things You Should Never Put In Your Garbage Disposal (Quick Scan)
Here’s a simple memory trick: if it’s hard, waxy, stringy, sticky, gummy, or not food, skip the disposal. That rule covers bones, pits, shells, nut butter messes, fibrous peels, coffee grounds, dough, flour, gum, and every bit of plastic, metal, or glass. Meds and paint do not belong here either.
- Bones, fruit pits, and hard shells
- Fats, oils, grease, gravy, and pan drippings
- Stringy greens, celery threads, onion skins, and corn husks
- Pasta, rice, oats, potato peels, and bread dough
- Coffee grounds and tea leaves
- Eggshells and shrimp shells
- Produce stickers, rubber bands, twist ties, and foil
- Bleach, lye, drain cleaners, solvents, and paint
- Large amounts of citrus peel or banana peel
What Can Go Down A Garbage Disposal Safely
Small amounts of soft food scraps are fine. Think plate scrapings of cooked vegetables, tiny fruit bits without pits, and small crumbs from the cutting board. Run a strong stream of cold water before, during, and after grinding. Feed slowly. Let the motor spin for 10–15 seconds after the noise ends to flush the line.
Prep Steps That Help
- Scrape plates into the trash first; treat the disposal as a final rinse aid
- Cut larger scraps into short pieces
- Remove pits, bones, and produce stickers before rinsing
- Use a sink strainer in the other bowl to catch strays
Fixes If The Wrong Item Slipped In
Stop, stay calm, and follow safe steps. Never reach in while power is live. A few careful moves clear most jams without damage.
Safe Response Guide
| Symptom | Likely Cause | First Steps |
|---|---|---|
| Humming but not grinding | Fibers wrapped the rotor | Cut power; use tongs to pull strands; press reset; flush cold water |
| Loud rattle or ping | Hard object inside | Cut power; remove with tongs; inspect with flashlight; reset |
| Standing water | Paste or sludge in trap | Bail sink; place bucket; remove P-trap; clean and reassemble |
| Harsh cleaner was added | Caustic fluid in chamber | Wear gloves/eye protection; dilute with plenty of water; call a pro if fumes persist |
| Repeat clogs | Grease layer or long branch run | Schedule a professional cleanout; switch habits and strain scraps |
Care Habits That Keep Drains Clear
Daily
After each grind, keep cold water running for 20–30 seconds. That extra rinse pushes grit past the trap. If sticky foods were rinsed, add a tiny drop of dish soap while the water runs.
Weekly
Grind a cup of ice to knock loose film from the chamber. Follow with a short flush. To freshen the rubber baffle, lift the flaps and scrub both sides with a brush and soapy water.
Monthly
Pour a quarter-cup of baking soda, then a quarter-cup of vinegar. Let it fizz for a few minutes, then flush with hot water. Skip bleach and skip lye products; they can pit metal parts and damage finishes nearby.
Not Just The Disposal: Think About The Whole Line
Even when the unit grinds well, the pipe still has tight bends and a small trap. Sticky paste and grease settle in those spots. That’s why many clogs show up a day or two after a big cook. Keep non-food trash out of the sink, strain scraps, and keep jars for grease by the stove.
Compost, Trash, Or Drop-Off: Smarter Routes For Scraps
Good For Home Compost
Fruit and veg scraps, coffee paper filters, tea bags without staples, and small plant trimmings break down well. Avoid meat, dairy, and oily foods in backyard bins.
Trash Works Better For
Bones, pits, shells, waxy peels, and sticky dough. Wrap messy scraps in newspaper to reduce odor.
Community Options
Many towns accept cooking oil and grease at local sites. Some curbside programs collect food scraps. Check your city page and place a small caddy on the counter so the routine sticks.
Cold Water, Hot Water, And Soap
Use cold water while grinding. Cold water keeps any stray fat firm so the impeller can break it into tiny bits that the strainer can catch. After grinding ends, let cold water run for a short flush. Save hot water for general sink cleaning, not for pushing grease through the line. Hot water melts fat in the chamber, only to let it re-harden deeper in the pipe, where reaching it is harder.
Model Claims Vs. Everyday Reality
Some premium disposals claim they can handle small bones or a stray fruit pit. The motor might spin through once, yet the shards still race into the trap and sit there. Over time those fragments snag peels and starch and form a wad. If you want years of quiet service, send hard items to the bin. Your unit will run smoother and the drain will stay clear longer.
Septic Systems Need Extra Care
If your home uses a septic tank, run an even leaner list. Disposals add ground solids to the tank that settle into sludge. Fats and oils float and can reach the field, which raises the risk of clogs in that network. Keep a small compost pail by the sink and keep most scraps out of the drain. Routine tank service keeps the system healthy and prevents yard headaches.
Pre-Grind Checklist
Before you flip the switch, do a 10-second check. Remove produce stickers, rubber bands, and ties. Pick out pits and bones. Cut long peels into short bits. Start strong stream of cold water, then feed small portions at a steady pace. Listen for pitch to level off before adding more. When the chamber sounds clear, keep the water running and let the motor spin a little longer to sweep the line.
Quick Recap: Keep These Out
Grease and oil, coffee grounds, eggshells, fibrous peels, starchy foods, bones, pits, shells, dough, flour, and any non-food item. When in doubt, use the bin or a scrap pail, not the disposal.