megalomania
May 2nd, 2004, 08:59 PM
I read a news report today that said those Pakistani individuals who were arrested a few weeks ago in England with the huge stockpile of ammonium nitrate were planning on adding osmium tetroxide to the explosive.
There is an article here: http://abcnews.go.com/sections/WNT/Investigation/poison_bomb_plot_040405-1.html
The only thing I knew osmium tetroxide was useful for was preparing vicenyl diols from alkenes. I am rather skeptical of its use in a bomb though. First things first, can it survive the high temperatures of an explosion unscathed? My guess is no as osmium tetroxide decomposes at higher temperatures to osmium dioxide. It does seem to have some uses for doping an explosive; it has a boiling point of 130 degrees C and is easily vaporizable well below that temperature.
I wonder what would be the ideal means of dispersion? Mix the OsO4 directly with the explosive, or place an explosive charge within a container of OsO4? I would have to vote on the latter as an inert diluent may decrease the performance of the explosive and give the osmium more chance to react during detonation. There is another article deriding its use here: http://www.newscientist.com/news/news.jsp?id=ns99994863
It has a rather high vapor pressure, and it would be a persistent gas after detonation, especially in an enclosed space. I found a website that compares the toxicity of osmium tetroxide with some common chemical weapon agents. Their conclusion was, based on osmium tetroxide�s high vapor pressure it is more comparable to sarin nerve gas. The website is here: http://www.navyseals.com/community/articles/article.cfm?id=3313 although the story looks like it was ripped from here: http://cns.miis.edu/pubs/week/040413.htm
That website gives the lowest lethal concentration of osmium tetroxide as 0.1 mg per cubic meter. A single Kg of this stuff vaporized in a small area like a shopping mall would spread a death cloud throughout the facility that would persist for hours. Simply hosing it down with water would suffice to decontaminate the area, but those in the vicinity, and first responders would get the worst of it.
The greatest downside to using osmium is its great cost. Osmium is found along with platinum, and is considered a rare metal. The previously mentioned website gives some costs and availability data. That website also stated osmium tetroxide is routinely sold as a polymerized mixture in batches greater than 5 g to reduce its vaporization hazard. To this I say it would be foolish for anyone to purchase osmium tetroxide directly. Rather one should obtain osmium powder or an osmium ore and extract it themselves. Osmium is quite readily reacted to osmium tetroxide in the presence of oxygen.
The navy seals website correctly concludes that osmium tetroxide is more of an intellectual curiosity than a viable weapon. A small explosive device with a limited quantity of osmium tetroxide obtained from a laboratory would add an extra dimension of lethality, but a large device and massive quantities of osmium tetroxide would be uneconomical.
It is the thinking behind using this kind of chemical that throws the authorities. Osmium tetroxide is but one of thousands of chemicals that could increase the lethality of an explosive device considerably. I am just surprised it has taken them this long to come up with the idea of using a doping chemical. I suppose since regular military doctrines forbid using such weapons nobody caught on to the idea.
Perhaps a better idea would be to disperse the osmium tetroxide via heating instead of via an explosive. A chemical or electrical heat source could be used. Something as simple as a coffee maker with a pot full of the compound could be plugged in someplace crowded and no one would know until hours later.
There is an article here: http://abcnews.go.com/sections/WNT/Investigation/poison_bomb_plot_040405-1.html
The only thing I knew osmium tetroxide was useful for was preparing vicenyl diols from alkenes. I am rather skeptical of its use in a bomb though. First things first, can it survive the high temperatures of an explosion unscathed? My guess is no as osmium tetroxide decomposes at higher temperatures to osmium dioxide. It does seem to have some uses for doping an explosive; it has a boiling point of 130 degrees C and is easily vaporizable well below that temperature.
I wonder what would be the ideal means of dispersion? Mix the OsO4 directly with the explosive, or place an explosive charge within a container of OsO4? I would have to vote on the latter as an inert diluent may decrease the performance of the explosive and give the osmium more chance to react during detonation. There is another article deriding its use here: http://www.newscientist.com/news/news.jsp?id=ns99994863
It has a rather high vapor pressure, and it would be a persistent gas after detonation, especially in an enclosed space. I found a website that compares the toxicity of osmium tetroxide with some common chemical weapon agents. Their conclusion was, based on osmium tetroxide�s high vapor pressure it is more comparable to sarin nerve gas. The website is here: http://www.navyseals.com/community/articles/article.cfm?id=3313 although the story looks like it was ripped from here: http://cns.miis.edu/pubs/week/040413.htm
That website gives the lowest lethal concentration of osmium tetroxide as 0.1 mg per cubic meter. A single Kg of this stuff vaporized in a small area like a shopping mall would spread a death cloud throughout the facility that would persist for hours. Simply hosing it down with water would suffice to decontaminate the area, but those in the vicinity, and first responders would get the worst of it.
The greatest downside to using osmium is its great cost. Osmium is found along with platinum, and is considered a rare metal. The previously mentioned website gives some costs and availability data. That website also stated osmium tetroxide is routinely sold as a polymerized mixture in batches greater than 5 g to reduce its vaporization hazard. To this I say it would be foolish for anyone to purchase osmium tetroxide directly. Rather one should obtain osmium powder or an osmium ore and extract it themselves. Osmium is quite readily reacted to osmium tetroxide in the presence of oxygen.
The navy seals website correctly concludes that osmium tetroxide is more of an intellectual curiosity than a viable weapon. A small explosive device with a limited quantity of osmium tetroxide obtained from a laboratory would add an extra dimension of lethality, but a large device and massive quantities of osmium tetroxide would be uneconomical.
It is the thinking behind using this kind of chemical that throws the authorities. Osmium tetroxide is but one of thousands of chemicals that could increase the lethality of an explosive device considerably. I am just surprised it has taken them this long to come up with the idea of using a doping chemical. I suppose since regular military doctrines forbid using such weapons nobody caught on to the idea.
Perhaps a better idea would be to disperse the osmium tetroxide via heating instead of via an explosive. A chemical or electrical heat source could be used. Something as simple as a coffee maker with a pot full of the compound could be plugged in someplace crowded and no one would know until hours later.