Chemical warfare, although not as feared as nuclear warfare, is just as deadly. The silent killing of the target is sometimes more terrible to imagine than nuclear warfare. Near the end of WW2, both the USA and the then USSR started manufacturing Sarin, a deadly nerve agent.
Before we start about Sarin, a short history lesson is due on the inclination of countries towards chemical warfare.
History of Sarin
Sarin was discovered in 1939 by German scientists attempting to produce more powerful pesticides. They instead synthesized four different nerve agents, called G-Series Nerve Agents, as they were produced in Germany. The four agents were GA (tabun), GB (sarin), GD (soman) and GF (cyclosarin), in the order of synthesis. Of these four, Sarin was easily the most toxic.
The formula for sarin was then passed to the chemical warfare department of the German Army, which immediately commenced production of sarin for the purpose of deployment in missiles and artillery. Although about 5000 kg of sarin was reportedly produced, the Germans decided not to use this against the Allied forces in WW2.
It then fell into the hands of both the USA and the USSR, both of whom started stockpiling for use in the advent of any future conflict.
Production of Sarin
Although sarin is extraordinarily deadly, it is not very difficult to produce. It is generally manufactured by reacting methylphosphonyl diflouride with isopropyl alcohol. Although hydrogen flouride is produced in this reaction, it is neutralized by adding isopropylamine. This method of production is so easy that it can even be used at the site of bomb deployment for some quick production of sarin.
Mechanism of action
The mechanism of action of sarin on animals is similar to the action of many insecticides. Sarin attacks the nervous system, by inhibiting the action of cholinesterase enzyme, which is used for nerve transmission. When this chemical is inhibited, it prevents the movement of acetylcholine, which acts as the nerve transmitter. This causes the muscles in the body to inordinately contract. Since it affects all the muscles in the body, the diaphragm is also affected, which causes death by suffocation.
Effects of sarin and treatment
The main danger with regard to sarin is that it is highly volatile. Concentrations of about 100 milligrams, in 1 cubic metre of air are easily lethal. Absorption through skin and vapor inhalation can easily cause fatalities. Death usually follows in a minute in the case of direct ingestion, unless antidotes, typically atropine and pralidoxime are administered.
Sarin is estimated to be about 500 times more poisonous than cyanide. A victim of sarin usually suffers from a runny nose, chest tightness and dilation of pupils. Next, there is difficulty breathing and the victim suffers from nausea and drooling. Slowly, more and more muscles pass out of the control of the victim, causing him to vomit, defecate and urinate, finally leading to convulsive spasms, and death.
Shelf Life and degradation of sarin
Sarin can be easily degraded into non toxic compounds in the presence of a high pH environment. Sarin also begins degrading automatically after a period of a few weeks. Contaminated sarin has a much lesser shelf life. Shelf life can be improved by addition of petroleum products to it. Mostly, sarin is only prepared in flight or on the way to deployment, by mixing the two precursors on the way, to create high grade sarin.
Sarin was listed as a weapon of mass destruction by UN resolution 687, and it still retains that status to date. The stockpiling of sarin was banned by the Chemical Weapons Convention, and is classified as a Schedule 1 substance, which includes substances which do not have any use outside chemical warfare.
The threat of sarin is negligible today, given how the materials for production of sarin are controlled. But that does not preclude the threat of terrorists stockpiling the nerve agent, with the aim of using it against mankind, nor does it prevent any country from secretly producing sarin. Either way, sarin is a substance which assures the doctrine of mutual assured destruction, and it is rightly ranked at the top along with substances capable of destroying humanity.