The sun is the secret to a smelly lunch box

The most effective way to get persistent odors out of a plastic lunch box is a baking soda scrub followed by a few hours in direct sunlight.

Plastic is porous at a microscopic level. Curry, tomato, or fish oils soak into those pores, and a normal wash just wipes the surface. So first, make a thick paste of baking soda and water, rub it all over the inside, and let it sit for an hour. Then wash it like normal.

The real knockout punch is the sun. Put the box outside in direct sunlight for a few hours. UV light breaks down the odor molecules and kills whatever bacteria are hanging around. This gets smells out that no detergent can touch.

Two things to avoid: boiling water (it can warp the plastic) and mixing baking soda with vinegar (they cancel each other out—you get bubbles, not cleaning). If the smell survives all that, a denture tablet soak is a weirdly effective last resort.

Your lunch shouldn’t taste like last Tuesday’s curry.