I feel stainless steel and glass (also fired ceramics) are the only safe way of storing water. All other containers will give of some chemicals or metal oxides to pollute the water.Plastic bottles of watter can put some pretty nasty stuff in your system, including: bisphenol A, polyethylene terephthalate, and styrene. The longer the water sits in those bottles, the higher concentration you are swallowing. We can all pretty well agree that pure water doesn't really have a shelf life - it can become contaminated pretty easily tho. So why does bottled water have an expiration date? Hopefully we have included water filtration methods in our preps. I myself don't like glass for storing water, but Aluminum and Stainless Steel water containers are on my wish list.