The BPA problem (and hence the Nalgene problem) was discovered because it was interrupting people's research on other things due to BPA leeching out of polycarbonate lab ware, causing differences between cell cultures grown in the plastic and those grown in traditional glass petri dishes when they were supposed to be behaving in an identical manner. http://www.fastcompany.com/magazine/132/the-real-story-on-bp...http://suss.stanford.edu/blog/?p=4119 That's Real Science.
If you'd like to dig it out for yourself, the search terms are: Stanford cancer bpa
(Yes, I'm well-aware that studies sponsored by chemical companies find no problem whatsoever. Quelle surprise.)
It's a long way from the cell culture to the human being when it comes to pharmaceutical effects. That is one of the main reasons it costs so much to develop new drugs--most compounds that produce promising effects in vitro are indistinguishable from placebo during human trials (if they even get that far).
The pharmaceutical industry actually tested BPA as an estrogen replacement decades ago, and did not adopt it because BPA did not produce measurable results. Today most of the BPA warnings are based on extrapolations from cell cultures. But based on the history of drug development such extrapolations are rarely valid. This is why U.S. regulatory agencies have not banned BPA; there just hasn't any solid evidence yet that BPA harms humans at the incidental levels of exposure most people experience.
If you'd like to dig it out for yourself, the search terms are: Stanford cancer bpa
(Yes, I'm well-aware that studies sponsored by chemical companies find no problem whatsoever. Quelle surprise.)