No boiling doesn't automatically destroy all bacteria, but I don't think sitting a premixed oxy-water solution in the fridge in a sealed container for a day or two is going to greatly increase the chance of infection. I don't shoot oxy, just heroin, so I did not know that it is destroyed by heat. (Can you do a cold shot, then? Why boil it at all?) Either way, it just doesn't seem like *that* dumb a thing to do. People are responding to this thread as though the OP is asking if they should use pond water in their shot. Pre-mixing water and storing it safely for later sounds like something I would've done before I got clean. I don't think it's such an outlandish thing to ask about... If you have access to sterile containers (I work at a hospital and used to steal them from work, for example.) then I don't think there would be any risk in doing this. The only potential risk I can think of is just the slight chance of bacteria growing in the water because it's sitting stagnant for some time. But if the water is sealed and refrigerated, the odds of bacteria growing in it are super low, especially considering it's just water. I disagree with everyone else posting on this thread. I think this is a totally safe thing to do.