Science

I know plastic is scary but guys, you don't need to replace your entire plastic container selection - you could just, decant your food into a different container before microwaving it? The microwave is what's doing this, not the fridge.

I'd recommend getting a small borosilicate/Pyrex dish like This. I've been using two of them my entire life (did none of you get taught that microwaving plastic with food make it go funny as a kid?) And they last a good while. Provided you don't drop them. I think IKEA sells them and I've seen them around in my local kitchen store in non-pyrex brands. Also they're oven and dishwasher safe too!

Also I don't reccomend hunting for vintage Pyrex here - old pyrex chips super easily and constant use and slamming the lid on will chip the edges to hell and back. The European formula isn't actually the same as the old one so it's fine but unless you like glass chips in your cupboard and super sharp edges, don't go for it.