I'm sure that the manufacturers would very strongly suggest NOT using 2% tincture of iodine for water purification since it's using it in a manner inconsistant with the label. However, the minute amount of alcohol is meaningless. The alcohol used is USP grade 190 proof ethanol (the drinking alcohol). It is far "purer" than any whisky. Remember, its made to pour on an open wound! It is certainly ok to drink a few drops in a quart of water! Wisconsin Pharmacal makes a fine product in Potable Aqua, but it takes longer to dissolve and the big bottle only treats between 6 and 12 gallons of water. It also decomposes after opening. They really rip you off with the PA Plus which is Vitamin C! ( I know, I ran it through a GC-MS one day when I was bored, the national institutes of standards database spit back a perfect match to vitamin C. Incidently, despite this being a less than exhaustive assay, it would hold up in court.) Another option is Polar Pure, which is nothing more than a bottle of iodine crystals in water. You add the correct amount of saturated iodine water from the bottle to your water supply according to the built in thermometer. I highly recommend this product, but it is bulky. It is the size of a 250 count aspirin bottle. Again, after the labeled "wait time" add some vitamin C to eliminate the taste. I have two water filters/ purifiers. The Pur scout and the Pur voyager. They are both excellent units, but they leave an iodine taste since they treat with iodine as well. The hiker, which does not treat with iodine is a best bet. Incidently, Pur offers a carbon element to remove organic chemicals and the iodine taste. You can make your own from aquarium charcoal in a bandanna. (I would wash it first by running luke warm tap water through it for about 20 minutes. ( use a kitchen strainer and coffee filter)) This charcoal will remove the iodine (remember to wait 5 minutes!) and alot of pesticides and other nasty chemicals. Frankly, I'm tired of carrying around alot of gear and have adopted some of the mentality of Ray Jardine. Alot of gear on the market, despite being well made and useful is just not needed. My bottle of 2% iodine and some vitamin C is all I ever use anymore save for a bandanna to remove sediment occasionally. My latest hobby project is a way to remove the sulfur smell/ taste from costal spring water using cheap readibly available stuff like mentioned above!<br><br>