Column: The Short, Ugly History of Nerve Agents
Recent events in Syria may cause readers to wonder, what is sarin and what is a nerve agent? Some historical and scientific context may help them grasp why the Syrian regime’s use of the weapon cannot be ignored.
In the mid-1930s the German organic chemist Gerhard Schrader was seeking to prepare new insecticides because Germany was unable to import the commonly used insecticide nicotine. In investigating “organophosphates,” which were thought to have some insecticidal activity, Schrader synthesized “tabun” in 1936 and “sarin” in 1938.
Schrader noted that a single tiny drop of tabun on the laboratory bench caused acute breathing difficulty; consequently, both tabun and sarin were deemed too dangerous to be used as insecticides. However, Nazi law required any potential military application to be reported to the government. Thus, both tabun and sarin (and later a third agent, “soman”) become chemical warfare agents of unprecedented toxicity.
From 1942 on, tabun was synthesized on a massive scale in Dyhernfurth, at a rate of 1,000 tons per month, and Germany stockpiled some 12,000 tons of this agent. In early 1945, the advancing Soviet army captured the tabun plant, dismantled it and rebuilt it in Russia. Also in 1945, American soldiers stumbled upon a sarin plant under construction in Falkenhagen and discovered one-half ton of sarin, which was brought back to this country for identification and study. Thus, tabun and sarin became the respective nerve agents of these two countries. Ironically, the U.S. was the first country to have, but never use, sarin in its chemical warfare arsenal.
Surprisingly, prior to these discoveries in 1945, no knowledge of chemical nerve agents was known outside of Germany. Needless to say, there is much mystery as to why Hitler never used tabun against the Allies.
Sarin is a highly volatile liquid organophosphate, the vapor of which causes rapid death, as we have seen in the photos from Syria. This chemical inhibits the vital nerve transmission enzyme acetylcholinesterase, which leads to the slowing of the heart, lowering of blood pressure, general convulsions and cessation of respiration, which is the usual cause of death.
Saddam Hussein killed some 5,000 Kurds in sarin gas attacks in 1988, and this agent was employed in 1995 by the Japanese terrorist cult Aum Shinrikyo in the abominable Tokyo subway attack that killed 12. The sarin synthesized by this cult was grossly impure; otherwise thousands might have been killed. Readers may recall the Utah sheep disaster in 1968 when 3,000 sheep were killed by “VX,” another lethal organophosphate nerve agent discovered in the United Kingdom in the 1950s, and accidently released during an aerial test by the Army.
Syria, no doubt, possesses other chemical weapons such as mustard gas, an insidious blister agent, and phosgene, a fatal choking agent, both of which caused thousands of casualties in World War I. But sarin has no equal as a lethal gaseous chemical agent. Our government must do everything possible short of invasion to prevent the further unconscionable slaughter of innocents in Syria by sarin.
Gordon W. Gribble is a professor of organic chemistry at Dartmouth College.