Prior to 2010, some Tupperware contained BPA. I think it was primarily the opaque items that are stiffer.
BPA is linked to obesity in both children and adults, developmental delay, heart disease, endocrine disorders (I think especially in girls), diabetes, breast cancer, and lots of other things.
There was also a woman in America who was making it her mission to test "everyday items" for heavy metals and other poisons. She's been doing it a few years now. I'll see if I can find a link - but it made me dispose of a good chunk of my Tupperware even though I found it useful.
We know so much now than ever before about toxicity but are still learning. SueDonim, please take a look.