0 Members and 1 Guest are viewing this topic.
In 1942, research undertaken under the auspices of the M-1000 Committee of the Canadian National Research Council established that anthrax spores could survive in sulfur mustard. The research had been undertaken with the goal of developing a combined biological and chemical weapon, the idea being that the blisters caused by the mustard agent would facilitate infection by the anthrax. The program was terminated without proceeding to weaponization.
By July, the Germans had accumulated enough of the new agent to use it, and on the evening of July 12, 1917 they carried out a bombardment of British troops near Ypres, Belgium. Because of the latent period before the effects of mustard make themselves apparent, the men in many gases didn't realize they were being gassed, or thought that the agent was not very effective. This impression was corrected within a few hours, as the latent period ended.The effects of the attacks with sulfur mustard were overwhelming. In the first week in which the Germans employed the agent, the British would admit 2934 mustard gas casualties to their various medical units - units which had been treating around 350 gas casualties a week in the period leading up to the attack. In the first three weeks in which the Germans employed their new agent the British would suffer 14,296 gas casualties.While the German expectations for its lethality were not borne out (only a bit more than 2% of mustard casualties were fatalities, which should be compared to about 8% for casualties from rifle fire), its effects were certainly not disappointing in the military sense. Indeed, had it been more lethal, it might have been less damaging. The need to care for mustard gas casualties placed burdens on the supply and medical systems that would not have been produced by fatalities. At the same time, the nature of the injuries it inflicted - the potential for blindness, the disfiguring and slow-healing lesions of the skin, and the rather painful death of those who had inhaled significant amounts - produced a strongly negative effect on the soldiers who had to suffer attacks using it.Nor did it help that gas masks provided only a partial protection against this new agent - a man wearing a mask could still suffer incapacitating burns if his skin was exposed. The uniforms of the period could absorb the agent while someone was passing through a contaminated area, and carry contamination to others while the original victim was still unaware of exposure.
At room temperature, mustard agent is a liquid with low volatility and is very stable during storage. The melting-point for pure mustard agent is 14.4 oC. In order to be able to effectively use mustard agent at lower temperatures, it has been mixed with lewisite in some types of ammunition in a ratio of 2:3. This mixture has a freezing-point of -26 oC. During the Second World War, a form of mustard agent with high viscosity was manufactured by means of the addition of a polymer. This is the first known example of a thickened CW agent.
Incidents are still occurring annually in the neighbourhood of Sweden where people risk injury from mustard agent. This largely involves fishermen who are exposed to mustard agent brought to the surface by fishing nets. The background is found in the dumping of chemical weapons after the Second World War in waters off the Danish and Swedish coasts. Many fishing ports in south Sweden and Denmark have resources to care for injured people and to decontaminate equipment contaminated by mustard agent. Certain resources are also available on the fishing vessels.Mustard agent is very simple to manufacture and can therefore be a "first choice" when a country decides to build up a capacity for chemical warfare.Apart from mustard agent, there are also several other closely related compounds which have been used as chemical weapons. During the 1930's, several reports were published on the synthesis of nitrogen mustard agent and its remarkable blistering effect. The mechanism of action and symptoms largely agree with those described for mustard agent. Germans and Americans started the military production of nitrogen mustard agent in 1941 and 1943, respectively, whereas the development in England was abandoned following an explosion. There is no verified use of nitrogen mustard agents as chemical weapons and their usefulness is restricted by these types of agents being unsuitable for storage.
Tris(2-chloroethyl)ethylamine is the organic compound with the formula N(CH2CH2Cl)3. Often abbreviated HN3, it is a powerful blister agent and a so-called nitrogen mustard gas (it is not a gas) used for chemical warfare. HN-3 was the last of the nitrogen mustard agents developed. It was designed as a military agent and is the only one of the nitrogen mustards that is still used for military purposes. It is the principal representative of the nitrogen mustards because its vesicant properties are almost equal to those of HD.Mode of actionNitrogen mustards react via an initial cyclization to the corresponding iminium salt. The rate of this reaction is pH dependent because the protonated amine cannot cyclize.ApplicationsHN-3 has found some applications in chemotherapy, e.g. for Hodgkin's disease, but it is mainly of interest for its military uses and is the only one of these agents that remains anywhere as a military agent. These agents are more immediately toxic than the sulfur mustards.