Interesting link.<br><br>>>> Under acidic conditions the oxidation half-reactions are … Under alkaline conditions, the half-reaction is … Reaction rates for the oxidation of constituents found in natural waters are relatively fast and depend on temperature, pH, and dosage. <<<<br><br>Basically, asking if there's a color chart for determining concentrations is a moot point as a concentration of "pink" will have different oxidation effectiveness under different water conditions. If I read the equations correctly, and it's been many years since I took chemistry, KMnO4 is more reactive in acidic water than it is in alkaline water. <br><br>>>> Potassium permanganate is a strong oxidizer and should be carefully handled when preparing the feed solution. … However, this dark purple/black crystalline solid can cause serious eye injury, is a skin and inhalation irritant, and can be fatal if swallowed.<br><br>I wonder if this alone would be a good reason not to include it in the kit, especially for Scouts.<br><br>>>> High dosage rates were required to accomplish complete inactivation of bacteria in three studies.<<<<br><br>This and other statements in the paper indicate that KMnO4 is not a cost-effective disinfectant for municipal water treatment. But I'm not sure that can be used to assume the same for a PSK. A high concentration in solution (pink to purple?) in the field may be effective treatment. However, the report states that long contact times may be needed for certain bacteria and viruses, up to two hours. Is that practical in the field for treating wounds?<br><br>I printed off the page to reread more carefully on the train tonight. But my initial thoughts are that maybe KMnO4 should not be included in my kit and that perhaps iodine may be a better antiseptic. Although I recall that it's more volatile and is caustic as well. I'll have to do some more reading and thinking.<br><br>Thanks, Tom<br>