We all drink/eat out of plastic bottles/containers at some stage but do the chemicals within the plastic leach into our food and water? Common sense would suggest that there would be some chemical leaching especially when the plastic is subjected to microwaves, strong acids/alkali or heat from dish washing but is this a concern?
A lot of plastic materials have recycling numbers imprinted into the plastic. For example most disposable water bottles are made from PET which is recycling number 1. This plastic if fine for single use but can decay allowing microbe contamination to grow which can be a health hazard. They should only be used for single use.
Since PET is meant to be single use we may turn to sports bottles which are commonly made of a harder plastic as they are designed for multiple use. These are commonly made from recycling number 7. Recycling number 7 contains a chemical called Bisphenol A. This chemical has been found to mimic hormones in our body. Bisphenol A has shown in rat studies to effect reproductive and fertility function. Pregnant or expecting mothers need to be particular aware of this problem as it could have similar effects in humans.
So what are you left to use? I recommend using glass where ever possible. It is easy to clean, won’t scratch and doesn’t have the potential problems of plastic. I would also keep away recycling numbers 3 and 6 as they also have other chemicals that maybe of concern.