The lid keeps food fresh. The glass keeps chemicals out.

Glass is your best bet for avoiding chemical leaching, but once you’re comparing glass, plastic, and stainless steel, freshness is all about the seal.

Plastic is the only one of the three with a real leaching problem. Heat and acidic food make it worse, and “BPA-free” mostly means they swapped in BPS or something similar that isn’t obviously safer. Glass and stainless steel don’t leach, period.

On freshness: the container material matters less than you’d think. Glass and steel are both non-porous, so they won’t absorb garlic smells or stain like plastic will. But none of them keep food “fresher” on their own — a loose lid ruins everything, regardless of material. Buy something with a properly sealing lid.

The practical trade-off is weight and microwaves. Glass is heavy and breakable but microwave-safe and lets you see what’s inside. Steel is lighter and tougher but won’t go in the microwave and can give acidic food a faint metallic taste. So glass for home, steel for the commute.

Pick glass if you reheat leftovers a lot — that’s where it genuinely beats the other two.