Using Iodine as a Sanitizer

[MarKee]

I had a customer tell me that they use iodine as a sanitizer.  Iodine is in the halogen family, along with chlorine and bromine.  I told the customer that if this method worked, I probably would have heard about it before.  Has anyone ever heard of this?  

[wmccall]

I guess you know it when you get in with a scrape or cut.

[CraigW]

Hmmm, I use an iodine based sanitizer for beer brewing, and it stains everything. Skin turns a nice yellow if you touch it, anything white turns colors if you leave it in it for any length of time. And that's at a very low concentration. Can't imagine using it in a tub unless it's a much lower concentration. For my sanitizing, I'm looking for contact times of only a couple minutes, so maybe it would be a low enough concentration to not stain.

[chem geek]

Iodine is not a strong oxidizer for getting rid of organics (bather waste).  So it needs to be looked at in the same way as N2 -- that is, as a sanitizer, but not an oxidizer.  So it would be used in conjunction with a non-chlorine shock (MPS) or with chlorine which would oxidize bather waste and re-activate the iodine as it got used up.  Additionally, it isn't used in pools because it doesn't kill algae and in sufficient quantities to be effective it gives the water a slightly green color.  It's more commonly used for personal (i.e. camping) drinking water disinfection, though its taste is objectionable so other products are typically used (such as a combination of Dichlor and sodium chlorite to produce chlorine dioxide).

Basically, if someone wanted alternative persistent sanitation, N2 would be a better way to go.  You'd still need either MPS or chlorine.

[TubsAndCues]

The bonus to using iodine is that it is non-irritating and non-bleaching.  

The down side, and this is why it is completely impractical for pool and spa use, is that it is nearly impossible to oxidize off the waste products.

I'd be very surprised is someone was actually using this.