Thank you phat, that brought it into focus for me.

Ok, so if you could, I'd think you'd want to break the chemical compounds down (or combine them) into the least harmful compounds, but I don't know if the chlorine based disinfectants we use even attempt to do that. I'm sure household chlorine does not.

I guess what bugs me is that I know chlorine is pretty bad stuff, and using it kind of reminds me of that Jack Black movie "Envy" and the "But where does the poo go?" line.

So I looked into it a bit more, and this article sort of confirms my suspicions. They call them "disinfection by-products" (DBPs).

I'm trying to figure out my options for a lighter, smaller alternative to my "Hiker" filter. Around here, boiling water would be best, but that takes time and fuel. I do that for my coffee and cooking, but I can't refill my drinking water while hiking that way.

The questions that remain then are how much free chlorine is left, and what is the ppm of DBPs and their toxicity when you use chlorine dioxide. The first two values are related, as the first goes down the second rises, and they are all variables that are affected by the water source.

So, you really have weigh using chlorine dioxide against some other method or not treating at all.

If you follow other methods this brings up the same questions, but when I think about using a steripen my gut feeling is that it wouldn't result in leaving harmful DBPs behind, or maybe not as many, or as toxic, and there'd be no (added) chlorine.

I'm not losing sleep over this, but I am curious.