G-agents decontamination

Cheng, T-C., DeFrank, J.J., Rastogi, V.K. (1999). Alteromonas prolidase for organophosphorus G-agent decontamination. Chem. Biol. Interact. 119-20 455-62. 

Alteromonas prolidase for organophosphorus G-agent decontamination. Chem-Biol Interact, 119-120, 455 162. 

Another V-agent of interest is Vx, called "V sub x." Another designation for Vx is "V-gas." The properties of Vx are similar to those of VX. It is nearly lOx more volatile than VX, but is very persistent in comparison to the G-agents. The molecular weight of Vx is 211.2. Listed values are calculated, information on this agent is limited. The physiological action, protection, and decontaminants for Vx are the same as for VX. 

Hurst, C.G. (1977). Decontamination. In Chemical Warfare Agents Textbook of Military Medicine (R. Zaitchuk, ed.), pp. 351-60. Office of Surgeon General, Falls Church. 

Further development of antigas ointments ceased in the 1950s because of their eight-fold enhancement in the percutaneous toxicity of G-agents (Cullumbine el al., 1954). The UK military use of anti-gas ointments as decontaminants was formally discontinued in 1959, when it was recommended that the best means of mitigating skin absorption was by physical absorption onto powders. Instead, attention focused on the development of new decontaminants. 

G-agents are readily decontaminated by basic hydrolysis in aqueous solution or in aqueous alcohol to improve solubility. At high pH, hydrolysis is virtually instantaneous. As discussed above, significantly enhanced rates of hydrolysis are observed in the presence of hypochlorite or peroxide ions. 

V-agents are less readily decontaminated than G-agents. Basic hydrolysis alone does not decontaminate VX (see above) owing to the formation of 41, which is still highly toxic (see equation 41) the V-oxide of VX is also very toxic. To effectively decontaminate VX, it is necessary to break the P—S bond. 

Chemical agent decontaminant (CAD) is the standard UK CW agent decontaminant and is prepared from sodium dichloroisocyanurate (FiClor, 85 g), sodium hydroxide (225 g) and boric acid (85 g) containing 1% sodium dodecyl sulphate (detergent) in water (9 litres). The activity of the solution is reduced by 50% after 1 h. The solution is freshly prepared from its individual solid components immediately prior to use and has a pH of 10.2. Like hypochlorite, FiClor is a source of electropositive chlorine. Although detailed studies into products and reaction mechanisms have not been carried out, it is likely that the decontamination of V- and G-agents by CAD follows a similar course to the reactions with hypochlorite under basic conditions. 

The microemulsion of the MCBD system consists of (by weight) tetrachloroethane (7%), cetyltrimethylammonium chloride (28%), water (60%) and a small amount of tetrabuty-lammonium hydroxide as co-surfactant. The reactive decontaminants are FiClor (4%) and sodium 2-nitro-4-iodoxybenzoate (IBX, 0.1%) in sodium borate buffer. IBX is added as a nucleophilic catalyst for the hydrolysis of G-agents The borate buffer (pH 10) is essential for the maintenance of the catalytic activity of the IBX (see above and Scheme 15). IBX has little catalytic effect on the hydrolysis of VX In the phase-transfer system, hypochlorite ion is transferred into the organic phase by the phase-transfer catalyst, tetra-butylammonium chloride. 

Chemical hydrolysis reactions are of two types acid and alkaline. Acid hydrolysis is of negligible importance for agent decontamination because the hydrolysis rate of most chemical agents is slow, and adequate acid catalysis is rarely observed.11 Alkaline hydrolysis is initiated by the nucleophilic attack of the hydroxide ion on the phosphorus atoms found in VX and the G agents. The hydrolysis rate is dependent on the chemical structure and reaction conditions such as pH, temperature, the kind of solvent used, and the presence of cata-... 

Wagner, G.W. and Y.-C. Yang. "Universal Decontaminating Solution for Chemical Warfare Agents," United States Patent 6245957, June 12, 2001. 

Although the vesicant properties of arsenical agents can be eliminated during decontamination, arsenic is an element and cannot be destroyed. Residual arsenical compounds may still possess significant toxicity if they enter the body through ingestion, or broken, abraded, or lacerated skin (e.g., penetration of skin by debris). 

Due to the limited extent of this paper, we mention only some positive results achieved in the orientation to two main directions i.e. to oxidative principles and to alcoholates in aprotic solvents. The research of oxidative principles (see e.g. [9]), involved the use of compounds with active chlorine, active iodine, peroxo-compounds, various mixtures of these compounds, as well as the use of oxidative agents with enhancing solubility and thus decontamination efficiency by adding detergents. It can... 

Decontamination Kit, Skin (M258A1) to avoid confusion, carries six packets within a kit, three Decon 1 carrying a mixture of hydroxyethane and phenol which adsorbs and neutralizes the G-series nerve agents, and three Decon 2 with a mixture of chloramine B... 

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