BPA did have a regulated limited. The problem is that the accumulative affect of BPA was never regulated. A single dose of BPA is not harmful. Steady exposure/consumption over many years is another matter all together.
In 1939, Swiss chemist Paul Hermann Müller discovered that DDT was an effective insecticide. It was used during WWII to control malaria and typhus. In 1948, Müller received the Nobel Peace Prize for his discovery of DDT as a contact poison on several arthropods. By 1962, there were concerns that DDT may be harmful. It took another 10 years to ban its use in agriculture. DDT was in use for 33 years, all the while its effectiveness was diminishing.
There is evidence that super weeds have invaded regions, that roundup loses its effectiveness on existing weeds, that it prevents fungus in the soil from breaking down nutrients for the plants and that crop yields are diminishing.
Granted, these studies and observations are not from Monsanto. They are from scientists either teaching in academia (one) or scientists that are involved in advising large scale growers or work for the USDA.
I'm not sure why one would be resistant to investigating whether or not GMO's and roundup are sustainable practices.
Measure twice, cut three times, start over. Repeat as necessary.