VX, hydrolysis

Currently, no monitoring program has been developed for agent degradation products. The assumption has been that breakdown products from decontamination or other activities are either less toxic or less persistent, or both. However, a recent evaluation prepared by the Army s Center for Health Promotion and Preventive Medicine and Oak Ridge National Laboratory has noted that a primary VX hydrolysis product, EA-2192, is more stable in water and is nearly as toxic as VX (Munro et al., 1999). Although EA-2192 may primarily be a concern for operations at Newport (where bulk VX will be destroyed by hydrolysis), it may also be present at other facilities if it survives normal VX decontamination operations. 

The most hazardous known VX hydrolysis products are persistent bis[2-(diisopropylamino)ethyl] disulfide, and highly toxic and persistent 5-[2-(diisopropylamino)ethyl] methylphosphonothioate. The decomposition of RVX gives rise to structural analogs of the above products bis[2-(diethylamino)ethyl] disulfide and 6 -[2-(diethylamino)ethyl]... 

Secondary reactions of the hydrolysis products, stabilizers, and impurities fonn additional chemical products during VX hydrolysis. Upon verification of 99.9999 percent agent destruction, the agent hydrolysate is transferred to an agent hydrolysate storage tank, where it is blended with energetics hydrolysate prior to secondary treatment. Additional details on the chemistry and analysis of the hydrolysate are discussed in Chapter 3 and Appendix B. 

Dejarme, L., and G.D. Lecakes. 2008. Bench-Scale Evaluation of VX Hydrolysis, TRRP 11, Test Report. Rev. 0. Aberdeen Proving Ground, Md. Program Manager for Assembled Chemical Weapons Alternatives. 

Unlike the G-agents, VX is relatively stable under acidic conditions. Although solubility is increased at lower temperatures, low temperatures decrease the rate of hydrolysis (Clark 1989). Trapp (1985) pointed out that, because of the low solubility of VX, hydrolysis data obtained under laboratory conditions may not be applicable to field conditions. VX in surface waters may sink and be adsorbed by sediment (Trapp 1985). A Henry s law constant of 8.19 x 10 atm-mVmole indicates that VX is essentially nonvolatile from water. 

Peterson, M.W., Fairchild, S.Z., Otto, T.C., et al., 2011. VX Hydrolysis by human serum paraoxonase 1 a comparison of experimental and computational results. PLoS ONE 6, e20335. 

During basic hydrolysis of VX up to about 10% of the agent if converted to EA2191 (diisopropylaminoethyl methylphos-phonothioic acid). Based on the concentration of EA2192 expected to be formed during hydrolysis and its toxicity (1.4 mg/kg dermal in rabbit at 24 h in a 10/90% by wt ethanol/water solution), a Class B poison would result. 

This material is an intermediate for production of VX (C01-A016) and is also commonly found as a decomposition product resulting from hydrolysis of VX. 

This material is commonly found as an impurity and degradation product from hydrolysis of VX (C01-A016). This material has been used as a simulant in government tests. 

Hazardous Decomposition Products During a basic hydrolysis of VX up to 10% of... 

The hydrolysis of VX and GB in hot sodium hydroxide solution and of mustard in hot water results in the formation of complex organic compounds. These molecules contain heteroatoms such as sulfur, chlorine, fluorine, and phosphorus, which, when oxidized, form acids. The excess sodium hydroxide present in the hydrolysate neutralizes these acids to form salts. For example, the following reactions are likely ... 

A similar preparative procedure was used to isolate tetrahedral complexes of bidentate donors (L = bipy or phen) [VL2](SCN)3. However, complexes of vanadium(lll) chloride or bromide with these same bidentate donors have stoichiometries depending on conditions.199 With excess of bipy or phen, complexes [VX JX were obtained. In EtOH or in MeCN two series of complexes were isolated. VC13LL (L = bipy or phen L = EtOH or MeCN) and [VC12L2]+ + [VCUL]-. In the reaction of vanadium(III) with phenanthroline202 203 or bipyridine204 there is evidence for extensive hydrolysis. Spectrophotometry was used to estimate the equilibrium constant (Kcq = 0.43) for the reaction in equation (7). 03... 

The chemical agents stored at the two bulk-only sites differ substantially (HD mustard agent at Aberdeen, Maryland, and VX nerve agent at Newport, Indiana). Therefore, different treatment process sequences were selected for use at the two sites. In both processes, the chemical bonds associated with agent toxicity will be destroyed by hydrolysis (with water for HD or aqueous sodium hydroxide for VX) (NRC, 1996a). However, in order to achieve rapid and... 

Hydrolysis of stabilizer N-N -diisopropyl carbodiimide, 17 2-3 Simplified scheme for the hydrolysis of VX, 17 2-4 Major hydrolysis pathways for mustard, 18... 

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