I had an issue with two packs of Lifesystems Chloride Dioxide solution recently. I left the bottles in the packaging while flying abroad, just in case someone got arsey (it's happened before with iodine tabs, back when you could buy them). On arrival, upon opening the packaging I found that, with both packs, the black bottle was empty and crusted with residue; while there was some liquid in the plastic bag I'd wrapped them in, there didn't seem to be enough to account for what should've been in the bottles. Make of that what you will, but I suggest you check bottle integrity before you fly. I'm boiling water as a result - inconvenient but I can live with it, just means carrying more weight.