Vapor pressure nerve agents

Significantly more persistent than other "G" series nerve agents but with a significantly greater vapor pressure than the "V" series nerve agents. 

For military purposes, unmodified carbamate nerve agents are classified as extremely persistent. Agents have negligible vapor pressure and they will not evaporate. Depending on the size of the individual particles and on any encapsulation or coatings applied to the particles, they can be reaerosolized by ground traffic or strong winds. 

GD is likely to undergo hydrolysis in most soils. As noted above, the rate of hydrolysis will be dependent upon temperature and pH. According to Morrill et al. (1985), evaporation is the primary mechanism for the loss of the GA and GB nerve agents from soil. Although the G agents are liquids under ordinary environmental conditions, their relatively high volatility and vapor pressure permits them to be disseminated in vapor form. Because of this volatility, GD is not expected to persist in soils. 

Nerve agents are absorbed both through the skin and via respiration. Because VX is an oily, nonvolatile liquid it is well absorbed through the skin (persistent nerve agent), although it can also be absorbed by inhalation. Thus, VX is more of a percutaneous threat than by inhalation, whereas the G agents (nonpersistent), which are also liquids, pose more of an inhalation hazard because of their vapor pressure. Sarin (GB) is the most volatile, but evaporates less readily than water, while cyclosarin (GF) is the least volatile of the G agents. 

M8A1 Alarm, M256A1 Kit, and CAM. However, since these agents have minimal vapor pressure, it may be difficult to effectively identify "V" series Nerve Agent vapors except in a confined or enclosed space. 

Physical Properties. Tabun is a colorless compound, which is said to have a somewhat fmity odor. The odor changes with decomposition so that with lesser amounts of decomposition the odor of cyanide (like bitter almonds) is apparent, whereas with greater amounts the odor of dimethyl-amine (like fish) is apparent. Tabun s vapor pressure is the lowest of all the G agents (approximately 0.04 mm Hg at 20°C). This suggests that tabun could be a relatively persistent threat at lower temperatures. Tabun has a vapor density of 5.6 relative to air and a liquid density of 1.08 g/mL (25°C). Its mp is —50°C, and its bp is approximately 240°C. It is three times as water soluble (approximately 10% at 20°C) as is VX, and also soluble in typical organic solvents (e.g., ethanol, diethyl ether, and chloroform). As with other nerve agents, dissolution in inert solvents (e.g., diethyl ether) enhances tabun s stability. 

Lethal Nerve Agent (GF) is a fluorinated organophosphate compound. Limited information is available on this nerve agent. The chemical formula is CH3P0(F)0C H . GF has a sweet, musty odor of peaches or shellac. It has a boiling point of 239°C (463°F) a vapor pressure of 0.044 mm Hg at 20°C a vapor... 

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