Well, I bought a 50 gallon Agricultural grade tank sold for pesticide use and use it along side my 15 gallon Y2K food grade water storage barrels. When I purchased it, it was sitting right next to the potable water/food safe tank that looked just like it and made by the same manufacturer. Guess what. It was cheaper and there was a manufacturers sticker on the tank indicating that it was food grade and had the United Nations numbers that it was manufactured in accordance with for potable water and shipping food. Many poly tanks are manufactured for both ag use and commercial food use made from the same plastics. Just be sure to check the labeling. When making large quantities of tanks it is cost effective to manufacture the tanks in the same baches. They just charge more for the "drinking water safe/food safe" tanks.