There are no doubt concentrations beyond which some sort of health issues manifest themselves, but apparently not till you reach far higher concentrations than we are talking about here according to those with which I have consulted. You can die from too much pure water as well. <img src="images/graemlins/grin.gif" alt="" /> This is simply what I have discovered in my research on this subject over the years and the answers I received I find satisfactory for my purposes WRT survival use. I have used many of these products in such manner without adverse effect. YMMV and far be it from me to try and convince you otherwise. You can always use alternate methods, larger containers or cut the tablets or amounts to maintain the original ratios, or die of dehydration if you so choose. <img src="images/graemlins/crazy.gif" alt="" />