I have some iodine tablets put up in survival kits in which I have tried to avoid anything that expires. I had the apparently false impression that iodine tablets last for a very long time if left sealed in their original sealed container, but the manufacturer states their tablets only have a four year shelf life.

I understand that Polar Pure, which I have used in the past is back in production. But their bottles are too large for my purpose. So my question is, could I re-use the old tablet bottles with iodine crystals, and how would I go about that?

I know I'd need some crystals and some sort of retaining screen that can stand up to iodine long-term. Would the volume of those small bottles allow for enough water to make up a "dose" for at least a liter of water, and how long would it take for additional water to be ready to use for the next dose?

Any thoughts or comments appreciated.

If you can still find iodine crystals, this is how I remember doing it. I borrowed this from another site. I think if first learned about this in a wilderness first aid class.

"Using Iodine crystals Water Purification
equipment
1. A 1 oz. glass jar with a bakelite cap (iodine is destroyed by contact plastic or metal).
2. A crystal of Iodine 0.1 gram minimum but more just insures a saturated solution.

1. Add Iodine crystals to 1 fluid oz. (1 tablespoon) of water (at 70 to100oF)
2. Close and shake for several minutes until you have a saturated solution with as much solid has dissolved as will dissolve.
Treating Water
3. To treat 1 liter or quart of water, carefully pour off 10ml (2 teaspoons) of the saturated iodine solution.
4. Caution: iodine crystals are VERY TOXIC! Do not tip the bottle over too far and spill crystals into the drinking water.
5. Let stand at least 15 minutes at room temperature or higher, making sure all of the interior surface including lid get treated.
6. Note: Iodine is not completely effective in destroying Giardia in cold water. The efficacy of iodine depends on contact time; 60 minutes at 60F, 30 minutes at 80F and 25 minutes at 115F for 100% destruction of Giardia cysts. If you have beavers, assume Giardia in the water.
7. Adding a pinch of Vitamin C (ascorbic acid) after the treatment helps eliminate the iodine taste of the water.
8. Iodine treatment appears safe for 3-6 months of use, but questions remain about long-term usage. It should not be used by persons with allergy to iodine, persons with active thyroid disease, or pregnant women."

I noticed that even my polarpure bottles can be a pain to store. The iodine still somehow escape. It will go through 2 ziploc bags and still taint the plastic tote i stored it in. It will even eat away at the aluminium layer of thick mylar bags.

So just beware of the corrosiveness of iodine crystals, when storing long term.

you might look into NaDCC (sodium dichloro isocyanurate)pool chlorine... currently endorsed by World Health Org... inexpensive, stores well, but difficult to titrate to small volumes of water less than 5gal... you will need test strips indicated down to small concentrations to give you a baseline amount... ppm (mg/l)

Here is what I currently use, along with, or instead of the sawyer squeeze mini.
This for backcountry springs and streams.

Liquid 2% Tincture of Iodine Add 5 drops per quart when the water is clear. Add 10 drops per quart when the water is cloudy. wait at least 30 minutes.

http://www.princeton.edu/~oa/manual/water.shtml

Thanks! That's really good and useful information.

Thanks. I know that iodine tincture does have an expiration date for medical use, but I wonder if and how that might affect it's ability to disinfect water?

That's one alternative, and I use it for my pool so I have it already, but I've found it breaks down rather quickly in the heat, as do the test strips. Thank you for this idea, but I'm really looking for something for quite small kits that are being stored long-term.

Thanks for the warning! I guess I've just been lucky so far, since I haven't had any leakage from any Polar Pure bottles that I've carried while backpacking (yet!), although I have dealt with leaking 100% DEET bug juice, which can also damage all kinds of things from plastic eyeglass lenses and watch crystals to high tech outdoor fabrics if it gets on them.

My idea was to recycle the small brown glass iodine tablet bottles I currently have for use with iodine crystals scavenged from a Polar Pure bottle, on the theory that if they were okay for iodine tablet storage, then they ought to be okay for iodine crystals and water storage, too. What I'm looking for is something very small, about the size of a bottle of iodine tablets, but that will last for a very long time in some small survival kits that will likely be stored without much if any periodic maintenance.

Check these out: http://www.ebay.com/itm/10g-99-8-Iodine-...=item20fc9056a5 if that's for emergency only. You can protect such an ampule in a piece of thick walled metal tube. I think, it should survive a very long time 100% sealed.

WHOA.... Hold on a minute! Alex, that's elemental iodine. Do you have any information that it is safe and equivalent to the iodine compounds/products meant for human consumption in water purification applications?

Hmm. I don't think there is any difference, except that tablets have some stabilizing filling making bare hands handling easier, and crystals in the Polar Pure are less pure. The elemental Iodine is what's so efficiently killing pathogens. Let me know if I'm wrong.

UPD: Google Polar Pure Ingredients. All it contains is 99.5% pure Iodine crystals.

I asked Potable Aqua a couple of years back what the shelf life of their iodine tablets was. It was one year from when the bottle was opened or four years from the date of manufacture. Which ever came first.