Tabun lethality

C.A.S. Registration Number Chemical Abstracts Service. An assigned number used to identify a material. CAS numbers identify specific chemicals and are assigned sequentially the number is a concise, unique means of material identification. A product of more than one component will have a specific number for each component (i.e., the CAS for lethal nerve agent GA, or tabun, is 77-81-9 while the CAS for the liquid nerve agent GB, or sarin, is 107-44-8, and 50.642-23-4). 

APPENDIX 18 Material Safety Data Sheet Lethal Nerve Agent Tabun (GA)... 

Organophosphorsus inhibitors have been developed as insecticides (paraoxon, parathion) and for chemical warfare (soman, tabun, sarin). They are extremely toxic and lethal either by cardiac arrest of general paralysis and subsequent suffocation. 

No doubt the British government had some scruples about the use of gas, and certainly by 1940 was well aware that in fact high explosive was a much more effective killer than any of the gases available to them. This was not the case in Germany. Starting in 1940 two new works were built, at Dyhernfurth and Gendorf, to exclusively produce mustard gas and the new lethal nerve agents, tabun and sarin.6... 

Ocular exposure to vapor causes miosis, conjunctival hyperemia, and eye pain within one to several minutes. Signs can last 2 to 3 days. Liquid tabun penetrates the eye quickly and can result in death nearly as rapidly as an inhalational lethal dose (1 to 10 min) (EPA, 1985c). Ingestion of the liquid causes muscarinic, nicotinic, and CNS signs about 30 min after mild exposures. The signs can last several hours up to 2 to 5 days depending on the amount of exposure. 

The G-nerve agents include GA (tabun, ethyl A,A-dimethyl-phosphoramidocyanidate), GB (sarin, isopropyl-methylphosphonofluoridate), GD (soman, 1,2,2-tri-methylpropyl methylphosphonofluoridate), and VX (o-ethyl 5-[2-(diisopropylamino)ethyl] methylphosphonothiolate). The V-type nerve agents are several orders of magnitude less volatile than the G-type agents and act primarily as a liquid via the percutaneous route for example, VX is several orders of magnitude more lethal percutaneously than sarin (Reutter, 1999). 

Respiratory paralysis. Tabun and sarin have been used as chemical-warfare agents, and parathion has been employed as an insecticide. What is the molecular basis of their lethal actions ... 

Respiratory paralysis. The neurotransmitter acetylcholine is degraded by a specific enzyme that is inactivated by Tabun, sarin, and parathion. Based on the structures below, propose a possible basis for their lethal actions. 

Physical Properties. Pure soman is a colorless liquid with a somewhat fruity odor. It has density 1.01 g/mL (20°C), vapor pressure of 0.27 mm/Hg (20°C), mp of —80°C, and bp of 190°C (85°C at 15 mm/Hg). Distillation is accompanied by decomposition that begins near 130°C. Soman s solubility in water is about 20% at 25°C. It is only about 20% as soluble in water as is tabun. With two different chiral centers, it exists as four stereoisomers (Benschop et al., 1985), each with a different toxicity. The lethal concentration (inhalation) in humans is estimated at approximately 25-50 mg min/m (Somani et al., 1992). 

Changes in blood pressure induced by OPC (sarin, tabun, DFP, thiophos, octamethyl, carbophos, mercaptophos, trichlorfon, DDVP) depend significantly upon a dose administered. High (lethal) doses induce a persistent fall in blood pressure, which is usually preceded by short-term hypertension. On the contrary, an effect of low doses can be accompanied by a rise in blood pressure [5, 6],... 

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