Sunlight is the real deodorizer for lunch boxes.

To stop lunch box smells, you have to break down the oil trapped in the plastic—soap alone won’t do it.

Plastic is porous. Tomato, onion, garlic, curry—those flavors soak into the surface and stay there even after a rinse. Soap removes the food residue, not the oil that’s already absorbed.

My go-to fix is a baking soda paste. Mix a few tablespoons with water, coat the inside, leave it overnight, then wash normally. White vinegar also works as a soak, and it kills bacteria too.

But the most effective thing is sunlight. Leave the clean, dry lunch box in direct sun for a couple of hours. The UV light breaks down the compounds that cause the smell. It sounds weird, but it works.

And if you’re tired of fighting plastic, switch to glass or stainless steel—solves the problem for good.