Potassium Permanganate in an oxidizing agent that is a common chemical used in synthetic organic chemistry. Because it is cheap, readibly available and effective, it has been abused by those that make illegal drugs in their basements, etc, which is why it has been somewhat harder to come by recently. It is also used by some municipal water treatment facilities. In my professiional opinion (I have a Ph.D in organic chemistry), there is little reason to carry this chemical other than as a stain (signalling) or as a chemical fire starter. A 79 cent bottle of 2% tincture of iodine is the poor, thinking man's choice. Five drops in a quart of room temp. water will kill most common pathogens in 5 minutes. Shake well with a loose cap. By adding a few small crumbs of ascorbic acid (vitamin C) AFTER 5 minutes, the chemical taste will be removed from the water. The residual sodium iodide is relatively harmless for the amounts that would be formed from reasonable use. If you have to have potassium permanganate, I suggest buying the chemical fire starting kit as sold by REI (www.rei.com) One component is potassium permanganate and the other is gyycerin in ethanol. Hope this helps. Andy<br><br>