It is important that the bottle you drink your daily water out of is not adding contaminants or allowing them into your water.  Glass is a very good container, but it is not always practical. So if you are going to use a plastic bottle it is essential that it is made of a good plastic that will not leech xenoestrogens or other toxins into your water, and that is not porous to micro-organisms. The best plastic to use is polycarbonate, also known as lexan. This is the plastic that baby bottles are made of. You can tell what a plastic container is made of by checking the recycling triangle on the bottom. Polycarbonate falls under the number 7. PET is most commonly used for water bottles in South Africa and this is designated by the number 1. It is not as stable as polycarbonate, but it is acceptable. Sevenpointfive sells polycarbonate bottles imported from overseas.