Hydrazine and HF can both kill you by skin contact or inhalation. The comparison isn't even close. The dangers of hydrogen are basically "oops I breathed so mu

Hydrazine and HF can both kill you by skin contact or inhalation. The comparison isn't even close. The dangers of hydrogen are basically "oops I breathed so much hydrogen that I got no oxygen for several minutes" or "oops I accidentally ignited it", both of which are easily avoided by basic safety precautions. In the context of filling a high altitude balloon that started this thread, asphyxiation is easily avoided by doing it outside, and ignition sources can be eliminated with a little care. This kind of fear-mongering--"could explode just because you looked at it funny" etc.--is irresponsible.