I stopped 30+ years ago after microwaving chili and it melted the side of the plastic container.
Fyi there's been stories about this for years (usually having to do with chemical contamination from the plastic) but the FDA never seemed to look into it.
Imo that's because Big Oil didn't want them to, because it would not only remove a HUGE source of their revenue but would also open them up to massive lawsuits.