Smell-proof is a cleaning habit, not a lunch box feature.

Any decent stainless steel lunch box will resist onion and garlic smells — what you actually want to avoid is plastic lids.

Stainless steel (look for 18/8 or 18/10) is non-porous, so the pungent compounds in onion and garlic don’t soak into it the way they do with plastic. That’s the whole reason to go with steel. But a box is only as good as its least-stainless part — if the lid is plastic, the lid becomes the thing that smells.

For the box itself, buy from a company that actually makes food-grade stainless containers: LunchBots, EcoLunchbox, PlanetBox, or Onyx. All of them use thick, fully-welded stainless steel with no interior coating. PlanetBox is pricey and a little kid-oriented; LunchBots and EcoLunchbox make the most practical shapes for adult lunches.

After a garlicky meal, wash it promptly with hot soapy water. If a faint smell still hangs around, rub the inside with a baking soda paste, rinse, and dry. That fixes just about every “my steel box stinks” complaint — it’s not the steel, it’s leftover oils needing to be broken down.

You’re overthinking the brand. Just make sure nothing plastic touches your food.