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Your garbage disposal feels like it can handle anything you throw at it, literally. But disposals are more delicate than they look, and the wrong item can mean a clogged sink, a jammed motor, or a call to a plumber. Here’s a clear breakdown of what to avoid, what’s actually safe, and how to keep your unit running smoothly for years. (If you’re cleaning house on kitchen appliance myths, our guide on what not to put in the microwave is worth a look too.)
Quick answer: What should never go in a garbage disposal?
Skip fats, oils, and grease; fibrous or stringy produce; starchy foods like pasta and rice; bones, shells, and pits; coffee grounds; large volumes of anything; non-food items; and harsh chemical drain cleaners. When in doubt, the trash or compost bin is the safer choice.
How a garbage disposal actually works (and why jams happen)
Despite the name, disposals don’t have blades. Inside the chamber, spinning impellers fling food against a stationary grind ring, which shreds it into small pieces that water carries down the drain. It’s a small chamber built for small amounts of soft debris, not a second trash can.
Two things make jams more likely: a lower-horsepower motor that can’t power through tougher scraps, and older or narrower plumbing that’s less forgiving of buildup. Disposals use impellers and a grind ring rather than blades, and feeding small amounts with cold water improves performance. Keeping the chamber clean also helps; see our tips on how to clean a garbage disposal for a simple routine.
Quick tip: Always run cold water during use and for 20 to 30 seconds afterward. Cold water keeps grease solid enough to break apart, while hot water can melt it, letting it re-harden further down the pipe.
What not to put in a garbage disposal (and why)
Fats, oils, and grease (FOG)
Bacon grease, pan drippings, melted butter, and shortening all seem liquid going in, but they solidify once they cool inside your pipes, coating the walls, trapping other debris, and eventually blocking flow. Running hot water doesn’t prevent this; it just delays where the grease resolidifies. This isn’t a minor household nuisance, either. The EPA estimated that 23,000 to 75,000 sanitary sewer overflows occur each year in the U.S., with blockages from fats, oils, and grease among the leading causes, and in Los Angeles specifically, approximately 70% of sewer spills are caused by grease blockages.
Alternative: Let grease cool, pour it into a can or jar, let it solidify, and toss it in the trash. If you cook with oil often, check for a local recycling program for larger volumes.
Starches that swell or turn pasty
Pasta, rice, oatmeal, bread, and potato peels absorb water and expand, even after they’ve been "ground up." That swelling can form a gel-like clog well past the disposal itself.
Fibrous, stringy, or tough produce
Celery, asparagus, artichokes, kale, corn husks, onion skins, and pumpkin or squash fibers can wrap around the impellers instead of breaking apart, forming ropey tangles that jam the mechanism.
Bones, shells, pits, and hard objects
Chicken and beef bones, crab and lobster shells, fruit pits, and nut shells are simply too hard for a disposal to grind. At best they dull the components; at worst they jam the unit entirely, and repeated jams over time can shorten its lifespan. If your unit has been struggling for a while, it’s worth reviewing when to replace a garbage disposal.
Coffee grounds
They look harmless, but coffee grounds compact into a dense, sludgy layer that settles in your trap and pipes over time.
Alternative: Compost them or toss them in the trash.
Eggshells (and large volumes of peels)
The inner membrane of an eggshell is stringy and can wrap around moving parts, and shell fragments contribute to sediment buildup. A stray shell now and then usually isn’t a problem, but it’s best to compost or trash them as a habit.
Non-food items and trash
Glass, metal, plastic, twist ties, produce stickers, paper towels, "flushable" wipes, and rubber bands don’t belong anywhere near a disposal. These items don’t break down and can damage the unit or create safety hazards.
Harsh chemical drain cleaners and bleach
Chemical drain cleaners are corrosive to metal components and rubber seals, and they can splash back and release harmful fumes. They also don’t do much for a mechanical jam; the actual obstruction is still there.
Alternative: Clear jams mechanically (see the troubleshooting section below),or use an enzyme-based cleaner that’s gentler on pipes. Call a professional if the problem doesn’t resolve.
What you can put in a garbage disposal (in moderation)
- Small, soft food scraps: Small bits of cooked vegetables or soft fruit scraps are fine. Cut larger pieces down first.
- Ice cubes and citrus peels (small pieces): Ice can help dislodge residue, and a small piece of citrus peel adds a fresh scent. Don’t overdo it with large peels.
- Cold water and a little dish soap: Running both together helps carry particles through and keeps the chamber cleaner.
Special considerations: Sewer vs. septic
If you’re on a municipal sewer system, the main goal is keeping FOG and solids out of the line to avoid contributing to neighborhood blockages and overflows.
If you’re on a septic system, disposals deserve extra caution. The EPA advises limiting or eliminating garbage disposal use on septic systems because disposals add solids that can lead to system failure and more frequent pumping. University Extension guidance similarly notes that garbage disposals can significantly increase the amount of solids entering a septic tank, requiring more frequent pumping. If you rely on a septic tank, consider composting food scraps instead of grinding them.
Safe alternatives and local disposal options
- FOG: Cool it, scrape pans into the trash first, then solidify and discard remaining grease. Some cities offer cooking oil recycling programs.
- Food scraps: Home composting or municipal organics collection is often a better option than the disposal. As of April 1, 2025, New York City requires residents to separate food scraps for collection, a sign that more cities are steering food waste away from sinks and landfills alike.
- Chemicals, paints, and solvents: These count as household hazardous waste. Oil-based paints, solvents, and pesticides are household hazardous waste and should never be poured down drains. Look up your local HHW drop-off location instead.
Quick troubleshooting: Jammed or clogged disposal
Safety first:
- Turn off the switch and cut power at the breaker before doing anything else.
- Never put your hand inside the chamber.
Steps to try:
- Use tongs or pliers to remove any visible obstruction.
- Insert the hex key into the bottom hub and turn it back and forth to free the flywheel.
- Press the red reset button on the underside of the unit.
- Restore power, run cold water, and test it briefly.
If the disposal hums but won’t spin, you notice a leak, or the breaker keeps tripping, stop and call a professional. Those are signs of a deeper issue, not a simple jam. For step-by-step help, see our guide on how to unclog your garbage disposal, and if you’re seeing water underneath the unit, check out garbage disposal leaking from the bottom.
Preventive care checklist
- Always run cold water during grinding and for 20 to 30 seconds afterward.
- Feed scraps in small amounts; never dump a full plate in at once.
- Do a quick visual check of the chamber before turning it on.
- Once a month, freshen it up by grinding a few ice cubes with a splash of dish soap, plus a small piece of citrus peel if you like. Check out our full list of garbage disposal cleaning tips for more ideas.
How Liberty Home Guard can help
Even with careful use, disposals wear out. When a covered garbage disposal fails from normal wear and tear, Liberty Home Guard can dispatch a licensed technician, typically within 24 to 48 hours after the service fee is paid. Every repair is backed by a 365-day workmanship guarantee, and coverage is available in all 50 states plus D.C. Explore our garbage disposal coverage or learn more about garbage disposal repair costs and coverage to see how a home warranty can help you protect tomorrow, today.
