Sunlight and vinegar are the real cure for a fishy lunch box.

Sunlight and white vinegar will fix a fishy lunch box faster than baking soda will.

Wash it with hot water and dish soap first. Fish and egg smell is carried by grease that clings to plastic, so if you don’t get the grease off, everything else is just covering up the problem. Scrub the lid too, and don’t skip the rubber gasket — that’s usually where the smell hides.

Then rinse or wipe the whole thing with white vinegar. Vinegar neutralizes the amines in fish and the sulfur compounds in egg, which are exactly the molecules your nose hates. Let it sit for ten minutes, then rinse.

And then put the box in direct sun for a few hours. UV light actually breaks down the smelly compounds. That’s the step everyone skips, and it’s the one that makes plastic smell genuinely clean instead of just citrusy.

Baking soda works okay in a pinch, but it mostly absorbs nearby odors rather than destroying the source. If the smell is baked into the plastic, go with degrease + vinegar + sun.

The smell is a grease problem — solve the grease, and the lunch box comes with it.