OT Don't read this (was Re: Altair MBL source)

Also a bit extreme. I've been in two complete and unwarned (the electronic pre-alarm sounding system was never activated because the contractors directly operated the release valve) halon dumps and the resulting mix was quite breathable. We did open the closed doors and air out the room (which requires a lot of effort as we're deep underneath Washington DC) of course, and the fire department came and helped in this. Others here may want to testify as to the resulting brain damage that I suffered but I generally think I'm doing just fine :-). A halon dump in a control center environment is quite impressive. Most of the celing tiles flew loose, loose papers on the console were blown everywhere, and for maybe ten seconds after the dump there was zero visibility. I'm not sure how other halon installations elsewhere work, but ours have a pre-alarm system that is supposed to warn occupants to get out for some number of seconds before the dump. There are also switches by the door (deadman style) that will let you hold off the dump. So clearly breathing the stuff isn't the healthiest idea in the world. But it's not quite as totally lethal as you and others would imply. Tim.