Quick Answer:
If the odor jumps up only while the disposal runs, the most likely cause is food trapped on the rubber splash guard or the baffle lips inside the opening, or residue inside the grinding chamber that gets airborne when water and air move. Remove and scrub the splash guard, clear any trapped food, and run cold water while grinding a small handful of ice (if your unit allows it) to knock loose residual gunk, then flush thoroughly.
Why This Happens
When the disposal is off, trapped food and residue sit in the baffle and on the rubber splash guard without much air flow. Running the disposal moves water and air through the opening and pushes trapped smells out. The grinding action can also disturb soft, decomposing bits inside the chamber and send the odor up the drain quickly. If the problem is wider than just the disposal opening it can be related to the sink trap or drain — see Kitchen drain smells like garbage — or seasonal effects on drains like temperature-related slow flow and odor concentration — see Odor worse in winter.
Step-by-Step What to Do
1. Turn off power
Before putting anything into the sink area, switch the disposal off at the wall switch and unplug it if possible. If the unit is hard-wired, turn the circuit breaker off. Never work with a disposal that could start while your hand is near the opening.
2. Remove and scrub the rubber splash guard
Pull the rubber splash guard straight up and out (it usually pops out). Scrub both sides with a small brush and dish soap until free of visible grime. Rinse and dry before placing it back.
3. Check the baffle lips for trapped food
Look under the splash guard at the baffle lips where food can get wedged. Use a small brush, a wooden tool, or long-handled tweezers to remove trapped bits. Do not stick your hand into the chamber without power locked out.
4. Use ice (if your disposal allows it)
With cold water running, drop a small handful of ice into the disposal and run the unit briefly. Ice chips help knock loose greasy residue from the impellers and chamber walls without using harsh chemicals. Check your disposal manual if you’re unsure whether ice is safe for your model.
5. Flush thoroughly
Keep cold water running for at least 15–30 seconds after grinding the ice to flush particles down the drain. Run the disposal briefly again to make sure the smell has cleared. Repeat the ice-and-flush step if necessary.
What Not to Do
- Don’t spray perfume or bleach into the disposal opening and call it done — those only mask or temporarily change the smell and don’t remove the gunk on the baffle.
- Don’t stick your hand into the disposal without confirming the power is off and the unit is disabled.
- Don’t ignore new noises or wet spots: if you hear unusual grinding sounds or leaks develop after you work on the unit, stop using it and get it serviced.
When to Call a Professional
- The smell returns immediately after cleaning.
- You can’t access the trapped food or the splash guard is damaged.
- The disposal makes loud grinding, rattling, or scraping noises, or you notice water leaking from the unit or piping.
- The unit won’t power on, trips the breaker, or shows signs of electrical problems.
Safety Notes
- Always disconnect power at the switch and, when practical, at the breaker before working on a disposal.
- Use tools (tongs, long-handled brushes) rather than bare hands to remove debris. If you must reach inside, make absolutely sure power is off and locked out.
- Wear gloves and eye protection when scrubbing greasy parts. Avoid chemical mixtures; do not mix bleach with other cleaners.
- Check the disposal manual for model-specific cautions (for example, whether ice is recommended).
Common Homeowner Questions
- Q: Why does the smell come only when the disposal runs?
A: Running moves air and water that dislodge trapped food and push odors out of the opening. - Q: Will vinegar or baking soda permanently fix the smell?
A: They can help neutralize odors short-term, but they won’t remove stuck gunk; scrubbing and flushing are needed. - Q: Is grinding ice safe for every disposal?
A: Many disposals tolerate ice and it helps dislodge residue, but check your manual—if unsure, skip it or call a pro.
For more related articles, see the Food Waste Odors & Bio-Buildup hub.