Dondo asked "When would Cl02 be contraindicated".
Honestly I don't have it in front of me. There was a discussion last year somewhere- maybe Backpacker mag forums about the high doses of Cl02 that are needed to quickly treat cold water not being recommended for children except in emergencies.
That, and my wife generally trying to protect the kids from synthetic chemicals as much as possible pushed me to find a non-chemical method of purification.
Hence the Steripen, with ClO2 tablets as backup in case the Steripen's magic death ray stops working.
I did a quick search trying to find an easy to follow MSDS on ClO2 and the risks to children. What I found instead was discussion of the "Miracle Mineral Solution" where Chlorine Dioxide is claimed to help the body rid itself of all sorts of infections, make your coat smooth and glossy, and makes its own gravy. It removes stains too!
I detect a little snake oil.

