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[0156] Polar-protic solvents are favorable for SN! nucleo› philic reactions, while polar aprotic solvents are favorable for SN2 nucleophilic reactions. In an SN2 reaction, the addition of a nucleophile and the elimination of a leaving group take place simultaneously. SN2 reactions can occur when the cen› tral carbon atom is easily accessible to the nucleophile. In contrast, an SN! reaction involves two steps. SN! reactions tend to be important when the central carbon atom of the substrate is surrounded by bulky groups, because such groups interfere sterically with the SN2 reaction and a highly substi› tuted carbon forms a stable carbocation. Apart from solvent effects, polar aprotic solvents may also be essential for reac› tions which use strong bases, such as reactions involving Grignard reagents or n-butyllithium. If a protic solvent were to be used, the reagent would be consumed by a side reaction with the solvent. 

[0157] The organic/aqueous solutions of the present inven› tion comprise one or more organic solvents selected from four ( 4) separate groups consisting of: 

[0158] Polar, aprotic solvents that do not contain oxygen but have large dipole moments, such as nitriles, haloal› kanes, and amides; 

[0159] polar, monoprotic solvents that contain one (1) --OH moiety, and have large dipole moments, such as the linear or branched-chain alcohols; 

[0160] polar, aprotic solvents that contain oxygen but to not have an acidic proton, such as ketones, aldehydes, ethers, furans, and dioxins; and 

[0161] polar, polyprotic solvents ( collectively, "poly› ols") that contain two or more -OH moieties, and have large dipole moments, such as the dials, trials and higher order polyols. 

[0162] Hybrid solvents that have the properties of two or more groups are included within the scope of the present invention. Exemplary hybrid solvents include 2-butoxyetha› nol, cyanocarboxylic acids, butanoic acid, and ethyl acetate. The organic/aqueous solutions of the present invention are further restricted to solvent mixtures wherein the volume fraction of water in the solution ranges from about 25% to about 75%, and the final pH of the solution is less than or equal to about 8.5. Alternatively, the pH can be maintained at less than or equal to about 8.0. The invention is active against all agents as pH values between about 7.0 to about 10.5; the buffer capacity is more effective at pH values between about 8.0 to about 9.0. However, for maximum active life, the pre› ferred embodiment is maintained a pH values from about 8.0 to about 8.5. The pH can further be maintained at a pH of about 8.5. 

[0163] Exemplary solutions include the alkanediol/water solutions, comprising one of the isomers of propanediol, butanediol, or pentanediol, and solutions made from linear monoprotic alkanols, such as ethanol or butanol or a hybrid of two solvent types such as 2-butoxyethanol. The linear or branched-chain monoprotic alkanols can have from 1 to at least 15 carbons. Additional properties of the organic/aque› ous solutions of the present invention should preferably include: 

[0164] the ability to dissolve, as a single isotropic solu› tions, full threat loads ofCBW toxants, where a chemi› cal threat load is 10 mg/m$^{2 }$or 10 mg/m$^{3 }$and a biological threat load is 10 $^{8 }$particles ( cfu or pfu) per mL; 

[0165] the capacity to dissolve sufficient amounts of polar perhydrolysis agents to enable stoichiometric per› hydrolysis of the dissolved toxant threat load; 

[0166] a low fluid viscosity over the temperature range -25° F.~T~125° F.; 

[0167] a low vapor pressure and a high Flash Point at temperatures >140° F.; and 

[0168] the ability to be sprayed onto a contaminated surface without having the composition of the decon› taminant solution change. 

[0169] Decontamination solutions of the present invention may be effectively deployed in neutralizing toxants over a temperature range ofbetween about -25° F. and about 140° F. Preferably, the decontamination solutions may be deployed and dispersed as aerosolized sprays over the range of tem› peratures of between about -25° F. and about 140° F. Other embodiments within the scope of the invention include decontaminants with improved hydrolytic activity at about -25° F., but which do not rapidly evaporate at temperatures as high as about 125° F. Rapid evaporation would limit the effectiveness of the decontamination solution and thus should be avoided, if possible. The solutions may also be applied directly to a surface by pouring or otherwise applying the solution to the surface. The working temperature range for decontamination can be adjusted by selection of the type and relative amounts of polar amphipathic solvents in organic/ aqueous solutions according to the total amount of peroxy› oxidant can vary according to the embodiments of the inven› tion. One skilled in the art having the present specification as their guide would know that the solutions made using polyprotic acids, such as the Group IV solvents, will have an entirely different buffering capacity as compared to solutions which comprise monoprotic solvents from Group II. Simi› larly, it will be known to one skilled in the art having the present specification as their guide that all equilibrium con› stants vary with temperature according to the van’t Hoff equa› tion, and that some solvents will be more likely to promote ionization of a dissolved acidic molecule if the organic/aque› ous solution comprises: 

[0170] a protic organic solvent, capable of forming hydrogen bonds; 

[0171] a solvent with a high donor number, making it a strong Lewis base; and/or 

[0172] a solvent with a high dielectric constant, making it a good solvent for ionic species. 

[0173] Dimtheylsulfoxide (DMSO) has a lower dielectric constant than water, is less polar, dissolves non-polar, hydro› phobic substances more readily, and has a measurable pKa range of about 1 to 30. Acetonitrile is less basic than DMSO. Also, acids are generally weaker and bases are generally stronger in this solvent. Some pKa values at 25° C. for aceto› nitrile and dimethyl sulfoxide (DMSO) are shown in the Table 5, where values for water are included for comparison. 

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