Because it is such a large place and includes Hawaii and Alaska I would think that if they use it interstate they would probably use it for export as well. I am not suggesting they don't use it or it is a bad idea, only that I have no idea as I have not seen it. As Jennifer has aid, there are a number of additives used to relieve stress, prevent the spread of problems from overcrowding, remove ammonia and a raft of other reasons. I would be curious to see what it is and the reason for it.