These days there are 3 different make of infant feeding bottle available in the market:
1. Standard Polycarbonate bottle (INR 50-100/- per bottle)
2. BPA free plastic bottle (200-400/- per bottle)
3. Glass bottle (240 – 400/- per bottle)
Like most first time parent, I was not aware of what BPA is (http://en.wikipedia.org/wiki/Bisphenol_A) and the triangle at the base of the plastic container with a number code (http://en.wikipedia.org/wiki/Resin_identification_code#Table_of_resin_codes.5B1.5D) was always greek & latin for me. However after going through several websites & forums I have realized that standard feeding bottle often contain Bisphenol A (BPA) which is added to make them transparent. Although BPA free bottles are available, but I secretly suspect here some other toxic chemical would be used. Hence I am going back to the age old glass bottles.
My wife was initially skeptical of using a glass bottle. Her concerns that a thick glass might crack when boiled, the bottle might shatter while the kid is playing with it & the glass might be too cumbersome for travelling. However after buying, I realized a FARLIN bottle, I realized that these concerns are unwarranted. It is made of thick enough glass to not shatter into fine pieces. Also as long as you immerse it in cold water and then heat that water, the bottle can withstand the changes in temperature. Also some expensive varieties have the volume measurement markings etched (instead of printed) this way it does not get washed away.
Simply put glass is inert & does not react or leach into the milk. Hence one should use it.