At home I have a halon bottle next to the pellet stove, another near the kitchen and a third in the bedroom.  My truck has one in the tool box and I need to put one in my wife's Highlander.  She has been thru training... boy, how did we do that without any drama?  The most curious one is the small halon bottle from the lavatory trash recepticle of an MD-81.  It was made by Walter Kiddeof Wilson, NC.  Total weight is 388 gr. and the "CBr F3" weight is 105 gr.  It is very ingenious in that it has two 1/8" dia tubes which point down into the trash bin should anyone get caught smoking and throw a still lit butt in there and start a fire.  The agent is released automatically as the two 1/8" tubes are closed with a solder of some kind which likely has the perfect melting point to release the gas just in time to prevent a big lav fire.  I removed it from the aircraft at the bone yard in Mojave just before the hulk was to be cut up for scrap.  I have been looking for a place to put it where its small volume would do some good. Under my truck hood is the best I have come up with so far.  Maybe behind the panel of N990Y would be better.
I think halon will displace just as much oxygen as Co2.  I would like a medical/chemical explanation why halon might be more survivable, all else being equal.
Great subject.
Walter Dodson  LIV-449