Sunlight beats baking soda for lunch boxes

Sunlight is the best trick for getting both smells and stains out of plastic lunch boxes.

Wash the box with hot soapy water first, then set it in direct sun for a few hours. UV light actually breaks down the organic molecules causing the tomato stain and the fishy smell. It’s not a myth, and it costs nothing.

Baking soda is fine but it’s mostly just a mild abrasive. It’s good for scrubbing off stuck-on gunk, and a paste of baking soda mixed with a little hydrogen peroxide will lift stubborn turmeric or tomato stains if you let it sit for 20 minutes. Plain baking soda alone won’t do much to a stain.

Vinegar kills odors but it doesn’t touch stains, and it leaves its own smell until it fully dries. Skip bleach too — it can leave a residue in the plastic that you don’t want near your food.

If a box still reeks after a wash and a full day in the sun, just throw it out. Plastic eventually gives up, and a new one costs less than a sandwich.