While shopping for best prices for Store Brand bleach, I found what I thought was a good deal only to see on the back of the label - "Contains 2.5% Sodium Hypochlorite". I've often found brands with no concentration information listed but this was the first one I saw less than 5.25%. Makes you wonder what those that aren't listed really are. Buyer beware when shopping for store brand bleach - it isn't all the same.