The worst things to put down a garbage disposal are fats and oils, coffee grounds, pasta and rice, fibrous scraps, eggshells, bones, fruit stones or pits, seafood shells, chemicals and non-food items. Some can jam or damage the food waste disposer; others pass through it but accumulate in downstream pipework.
Items to keep out
- Fats, grease and cooking oil: These can cool, congeal and coat pipes, trapping other waste and restricting the drain.
- Coffee grounds: Fine grounds can settle and combine with grease or residue to form dense build-up.
- Pasta, rice, oats and potato scraps: Starchy foods absorb water, swell or become sticky, potentially obstructing the chamber or drain.
- Fibrous scraps: Celery, corn husks, onion skins and large amounts of peel can tangle around internal components or bind together downstream.
- Bones, fruit stones, large seeds and seafood shells: Hard waste can jam or strain the mechanism, while fragments may lodge in pipework.
- Eggshells: They do not sharpen the disposer. Shell fragments and membranes add waste that may contribute to build-up or tangling.
- Non-food items: Glass, metal, cutlery, plastic, paper and packaging can jam or damage the unit and create sharp fragments.
- Paint, solvents, medicines and harsh chemicals: These should not enter a food waste disposer or household drain. Corrosive drain cleaners may also damage components and create a chemical hazard.
Risk varies by quantity and disposer design, so follow the manufacturer’s instructions. Material that passes through the unit can still obstruct the connected plumbing.
Safer disposal
Scrape solid food into general waste or an organics bin where accepted. Let fats and oils cool, then place them in a sealed container for disposal according to local council guidance.
Keep medicines, paint, solvents and other chemicals in their original containers and follow current product-label, pharmacy, council or NSW disposal directions. Recycle packaging only where your local service accepts it.
Safety warning: Never reach into a garbage disposal, even when the wall switch is off. Sharp components and electricity present serious risks. Isolate the appliance from its electrical supply only if you can do so safely; otherwise stop and contact an appropriate technician. For a jammed unit or blocked connected pipework, contact our Sydney plumbing team rather than attempting an internal repair.