When you buy the stuff, it either is in a 2% concentration, or 4% concentration (most is 2%) you then dilute 1 flow (3 tablespoons) in 1 gallon of water. it is best to use distilled water but is not necessary. once it has been diluted it is good for about a week (2-3 if using distilled water). When diluted it is safe to use and doesn't need to be aired out or anything like that. I just mix some up and spray down the enclosure, wait 5 minutes then wipe it up. I use it every time one of my snakes pees or poops. (But I am using corrugated wrap substrate you would use it less often with aspen/eco-earth/cypress)
Here is a MSDS report on the stuff (Material Safety Data Sheet)
Thanks for the MSDS. Where are you getting the life expectancy for a mixed solution? I scanned the sheet and didn't find it. I've heard the 1-3 weeks from a couple other people too but haven't been able to identify the source.