From a practical perspective for short term use it just isn't an issue. I have spoken with all the manufacturers and a number of independent authorities and all have said don't worry about it. Obviously, taste may be an issue for some, but there are no negative health concerns for short term use. Use those levels for a month or two and you might possible have some issues, maybe. Need to find something else to fret about. <img src="images/graemlins/smile.gif" alt="" />