Skip the plastic. Get a stainless steel lunch box.

Stainless steel is the only lunch box material I’d trust to avoid BPA, phthalates, and the rest of the chemical soup.

Here’s the thing about “BPA-free” plastic: it’s mostly marketing. When they removed BPA, a lot of manufacturers swapped in BPS or BPF, which aren’t proven safer. Phthalates are a whole separate category of plastic chemicals that deserve the same suspicion. So if your goal is “free of harmful chemicals,” you don’t want a cleaner plastic. You want no plastic.

The best options are PlanetBox, LunchBots, and U Konserve. PlanetBox is the big name in kids’ bento trays—all stainless steel, sectioned compartments, nothing plastic touches the food. LunchBots makes simpler stainless containers if you’d rather pack your own combo. U Konserve uses stainless with plastic lids, which is a minor trade-off, but I’d still take it over a fully plastic box.

Silicone is the runner-up. Food-grade silicone, like Stasher bags or silicone bento boxes, is inert and doesn’t have the same leaching concerns as plastic. I think it’s fine. But stainless is the sure bet because there’s no question about what’s in it.

PlanetBox runs $60–80, so it’s not a cheap purchase. It lasts for years and won’t degrade into your kid’s lunch. That’s not where you save six bucks.