You have probably heard a lot about baby bottles and toys made with BPA (Bisphenol-A), PVC and other toxic substances, that are being linked to hormonal issues and cancers. I have posted on this in the past. Glass baby bottles, stainless steel water bottles and sippy cups are selling out in some areas. The plastics seem to cause the most problems when exposed to hot substances or liquids. You can identify the most dangerous plastics by turning the item upside down and looking for the number inside the recycling triangle. The number 7 is not lucky in this application. It is the most likely to leach the chemicals that are causing the stir. I have attached an overview of the problematic plastics that I found on Wikipedia. I know Wikipedia is not always the most accurate source of information, but most of the information in this overview seems consistent with what I have read from other sources. I like the Wikipedia approach, because it is very comprehensive and easy to follow. Feel free to add your feedback on this topic. If you are looking for stainless steel water bottles, check out my recommended products on the sidebar. Personally, I am going old school and trying to use more products in glass and cardboard containers or fresh foods that don't require long term packaging. Good luck!