Back in my Prime days, when we got our Halon system, the salesman demonstrated it at their cost after installation. Triggering it deliberately, the result was as you describe. Additionally, boxes of greenbar that were open had the top layes of paper sucked out of the box, without breaking the perfs, sending it flying. He stood in there for 15 minutes, lighting matches which went out immediately, so we could see how well it worked. He drove away in his car, didn't crash or die. As it was explained to me, Halon is safe, but under temperatures that would kill anything organic, it can transform to a deadly gas. The joke was that the gas didn't kill you, but the reason you weren't supposed to be in the room if you had to trigger it manually was to avoid the shrapnel when the spheres exploded. Actually, I think one of the CDC disk drives went offline. Again, we were told, given the choice of breathing air or Halon, choose air everytime. But Halon was safe and we didn't need to worry. You can buy small Halon extinguishers still, but only at your local civil airport for your plane. I have recently heard, however, that there is a replacment gas that does just as well, but can't recall its name. Does seem that it starts with an "H", though. regards, -doug q