Hmm, I wonder...is the bottle of Chlorox bleach under my sink certified by the EPA as a water purifier? I had never even really thought of this question until this post. I just checked and it doesn't mention water purification anywhere. In fact, one of the first statements is that it is a federal crime to use the product in ways not mentioned on the product label, which I presume would include water purification. And yet every phone book and disaster/emergency preparedness booklet or website will advise people to have household bleach on hand on hand to disinfect water in case of emergency.

There's no "perfect" water purifier. Some don't neutralize all classes of the bad things. Some are expensive. Others could be toxic if used long-term. Other have short shelf lives, doesn't work well with cold water, the waiting time is too long, etc. etc. Strictly from a practical standpoint, Aquatabs seem no less effective, or put another way, is as effective, as other methods commonly used. As long as you are aware of the strengths and weaknesses, a dichloroisocyanurate-based product is a legitimate choice.

However, whether it's legal to sell that product--that's an entirely different situation. And in this situation, it seems like Aquatabs can't be sold as a water purification product in the US since, as Doug points out, it doesn't pass the EPA's standard for water purification, which includes Crypto. But neither does household bleach. Yet both dichloroisocyanurate and chlorine are used to disinfect municipal water supplies in different places around the world.

Anyway, as a vendor, I guess you shouldn't be selling these to Americans (well, I don't know EU law regarding this and if it exposes you to any liability). But as a US consumer, it's a more open-ended question about whether to purchase a non-EPA approved water purifier. Like Doug pointed out, it's not a totally clear cut decision in this case, but neither is household bleach, if you use the same standard.

Actually, thanks to ArmyRangerRick for asking the question. It's been interesting thinking about how the Aquatabs question applies to other water purifying techniques or products that we just take for granted.