My bottle here says "contains 1,1,1,2-tetrafluoroethane. Not flammable, but not very good for you either.
I prefer Nitrogen.
PE
PE - as far as not being very good for you, 1,1,1,2-tetrafluoroethane, also known as REFRIGERANT 134A, should have about the same health issues as nitrogen. Death by suffocation is the biggest concern for each of them, as they are both asphyxiants at high concentration.
While 1,1,1,2-tetrafluoroethane is not a freon, as freons are chlorofluorocarbons and there is no chlorine in it, it is very similar. It is fairly unreactive - perhaps behaving more like a gaseous teflon, if there was such a thing...
I have used Dust Off, and Beselar used to make a product called Xtend-All or something like that which was a freon. They work well. Just make sure you have bottles that are resistant to gas permeation.
I also have a nitrogen tank now. I use it for topping off bottles, and for purging the Jobo tank when processing with pyro-based developers.