Quick answer: Empty the bin, inspect the liner, lid, rim, and bottom for leaks or sticky residue, then wash with warm water and mild soap. Rinse and dry every surface completely before adding a new liner. If the odor returns while the bin is clean and dry, inspect the surrounding cabinet or floor for a hidden leak.
Find the residue that the first wash missed
Odor often stays in the parts that are easy to skip: the underside of the lid, the rim where the bag folds over, the handle, and the bottom seam. Remove the liner and check the floor beneath the bin as well. A small leak from food packaging can run down the inside and sit under the liner.
Wipe the outside too, especially if the bin is stored in a cabinet. Do not assume the smell is coming from the plastic itself until you have checked the nearby wall, floor, and cabinet base.
Wash in a simple order
Take the bin to a place where runoff can be controlled. Remove loose debris, then use warm water and a small amount of mild soap. A soft brush can help around the rim and lid hinges. Rinse until the water runs clear and wipe away standing water from the base.
Dry the bin upside down if the material and location allow it, or towel-dry the interior and leave the lid open. Moisture trapped under a lid or in a bottom ridge can bring the smell back even when the bin looks clean. Never mix bleach, acids, ammonia, or other cleaning products.
Check the room if the smell returns
After the bin is clean and dry, use a new liner and watch for another leak. If the odor returns immediately, look under the sink, behind the bin, and around nearby plumbing. A damp cabinet or floor can make a clean trash can seem like the source.
Replace a cracked liner, damaged lid gasket, or heavily degraded bin. For broader odor troubleshooting, read our hidden-buildup checklist and the under-sink inspection guide.