I won't argue with folks about the recent discussion of Halon but many of the "facts" being offered are just plain wrong. Nor will I agrue the merits of using a system in a car (thats a personal decision) but at least people should know the facts. Halon is used extensively in aircraft in occupied spaces and I'm quite familiar with its properties. It is of low toxcicity and *does not* displace the O2 in the ambient atmosphere. It only breaks the chemical chain required for combustion. Its is so effective (especially the 1211/1301 blend which is prefered because it makes its own pressure and will not lose its propellant as in N2 powered systems), that the concetration needed for suppression doesn't affect the level of O2 needed for respiration. A dry chemical agent would be the worst thing to use and CO2 will cause aphxyiation *far* quicker than Halon, due to the increased concentration needed. Thats the trouble with boards like this, too many "experts". Thats a shame when the info is so readily available. I suggest you read: http://www.h3r.com/halon/ Its where I buy my systems and these people know the facts.