Okay, I guy I've known almost all my life is trying to sell me some water barrels. White plastic 55 gallon barrels. He said they had phosphoric acid in them, that it is used both in soft drinks and in wine making (something to do in the oak barrels maybe?) and that his barrels have been cleaned, are very safe, yada, yada, yada. Since any I buy might be used for livestock water I want to be quite sure that they are safe, though I have always trusted this person. Any thoughts?