The plastic industry defends the use of bisphenol A in polycarbonate plastic, including baby bottles, because of its long history of supposedly safe use. That defense is based upon certain animal studies that focus on the dose of bisphenol A and lifetime exposure assessments.
But is that the correct analysis? Many environmental toxicologists and epidemiologists have begun to re-think the analysis of exposure. They used to focus on lifetime exposure, but are now questioning this analysis. They are now evaluating at early exposures that may result in diseases late in life. The early childhood exposures may activate genes or damage DNA in the womb or during childhood.
And because of that debate, it seems prudent to reduce exposures for children whenever possible For example, for bisphenol A, I don't know whether or not early childhood exposure is safe. But I do know that there are BPA free baby bottles available, so I can choose such a bottle.