Bisphenol A is one ingredient that makes polycarbonate and epoxies work the way they do. A lot of people have fretted and expressed some concern about bisphenol A bioaccumulating – I can just about guarantee you’re toting some around in your fat. More persistent and toxic to aquatic life is a derivative of bisphenol A – tetrabromobisphenol A.
Hanging a lot of halogens off of a compound is a pretty good way of making a flame retardant – we used to make amazing fire extinguishers with stuff called Halon (that link’s highly recommended). I am told they were so good you could set up flame sensors and fill a room with them before a fire barely became visible (I’m talking lighting a match). They also required a low enough concentration that they could be used to extinguish a fire, while keeping enough oxygen in a room to support life.
Sadly, they destroy ozone quite effectively, so they were pretty comprehensively banned. Now we flood rooms with suffocating amounts of CO2. Halon may be the most effective fire suppressant the world will ever know – it is hard to conceive of something that works by as effective a mechanism.
Anyway. Tetrabromobisphenol A is like a solid halon – the idea is you mix a few percent in with your regular bisphenol A and make a flame-retardant polymer. There are the aforementioned tox and persistence problems, however. Always a trade-off…