That is true, chemical purification will do nothing against non-biological agents.

About the only thing I know of that will take care of chemicals is active carbon filtration, like the MSR Waterworks, but I have doubts to its effectiviness.

I think the real question is "How much of a threat is chemical contamination Vs. Biological?"

In my opinion you are more likely to come across water contaminated with fecal coliforms and other nasty critters in water sources from cross contamination inthe miles of broken pipes, or flooded waste water lift stations than you are from oil, gas, or other chemical contaminates. (You should be smart though, I wouldn't be trying drink water flowing out of the ground by a gas station <img src="/images/graemlins/wink.gif" alt="" /> )

Secondly, as bad this sounds you can survive drinking some minorly chemically poluted water with out to many adverse effects. You drink biologicaly contaminated water and you are definately going to have adverse effects. So the risks from biological are far greater than chemical.

Either way I do agree that your best bet is to carry your own. Which is why I supported the 1/2 liter of water. But that's just a stop gap measure until you can either locate additional water and to hold you over till you can sterilize that water or get the hell out of Dodge.

Chlorine Dioxide tabs are small, have a shelf life of 3 years, not to expensive, and will kill anything including cysts and Giardia that Iodine tabs won't take care of. The biggest draw back is your looking at a 4 hour wait for it to do its thing. Carring a few tabs seems like a worthy investment to me.

Also you have to consider that even after you get out of the disaster area most of the surrounding areas an d towns get their water and waste water removal from the city's water system. If that is crashed or cross contamination has occured your still looking at treating or boiling.