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[0066] For further information on organic liquid-contain› ing solvent components, the interested reader is directed to U.S. Pat. Pub!. No. 2016/0073628. 

[0067] The composition is somewhat acidic. Generally, the composition has a pH of no less than 4.5, and certain embodiments can have a pH ofno less than 4.55, 4.60, 4.75, 4.80, 4.85, 4.90, 4.95 or even 5.00. The composition also generally has a pH ofno more than 6.75, 6.50, 6.25, or even 6.00. Ranges of pH values employing each of the lower limits in combination with each of the upper limits are envisioned. The composition can have a pH value of 5.5–1. 0, 5.6–0.8, 5.7–0.8, 5.75–0.8, 5.8–0.75, and 5.75–0.75. 

[0068] Acidity can be achieved by adding to the solvent component (or vice versa) one or more acids. Strong (min› eral) acids such as HCl, H$_{2}$ SO$_{4}$ , H$_{3}$ PO$_{4}$ , HNO$_{3}$ , H$_{3}$ BO$_{3}$, and the like or organic acids, particularly organic polyacids, may be used. Examples of organic acids include monoprotic acids such as formic acid, acetic acid and substituted vari› ants ( e.g., hydroxyacetic acid, chloroacetic acid, dichloro› acetic acid, phenylacetic acid, and the like), propanoic acid and substituted variants (e.g., lactic acid, pyruvic acid, and the like), any of a variety of benzoic acids (e.g., mandelic acid, chloromandelic acid, salicylic acid, and the like), glucuronic acid, and the like; diprotic acids such as oxalic acid and substituted variants ( e.g., oxamic acid), butanedioic acid and substituted variants (e.g., malic acid, aspartic acid, tartaric acid, citramalic acid, and the like), pentanedioic acid and substituted variants (e.g., glutamic acid, 2-ketoglutaric acid, and the like), hexanedioic acid and substituted variants (e.g., mucic acid), butenedioic acid (both cis and trans isomers), iminodiacetic acid, phthalic acid, and the like; triprotic acids such as citric acid, 2-methylpropane-1,2,3- tricarboxylic acid, benzenetricarboxylic acid, nitrilotriacetic acid, and the like; tetraprotic acids such as prehnitic acid, pyromellitic acid, and the like; and even higher degree acids (e.g., penta-, hexa-, heptaprotic, etc.). Where a tri-, tetra-, or higher acid is used, one or more of the carboxyl protons can be replaced by cationic atoms or groups ( e.g., alkali metal ions), which can be the same or different. 

[0069] In certain embodiments, preference can be given to those organic acids which are, or can be made to be, highly soluble in water; acids that include groups that enhance solubility in water (e.g., hydroxyl groups), examples of which include tartaric acid, citric acid, and citramalic acid, can be preferred in some circumstances. In these and/or other embodiments, preference can be given to those organic acids which are biocompatible; many of the organic acids listed above are used in preparing or treating food products, personal care products, and the like. 

[0070] The composition advantageously need not include an oxidizing acid to have lethal efficacy against endospores. Many oxyacids, such as perchloric, chloric, chlorous, hypochlorous, persulfuric, sulfuric, sulfurous, hyposulfu› rous, pyrosulfuric, di sulfurous, thiosulfurous, pemitric, nitric, nitrous, hyponitrous, perchromic, chromic, dichro› mic, permanganic, manganic, perphosphoric, phosphoric, 

phosphorous, hypophosphorus, periodic, iodic, iodous, etc., are considered to be oxidizing acids. Organic oxidizing acids include, but are not limited to, peracetic acid, peroxalic acid and diperoxalic acid. 

[0071] If an oxidizing acid is included in the composition, those which have relatively high pKa values (i.e., are not considered to be particularly strong acids) and positive standard potentials (E 0 red) are preferred. The former permits production of a composition that has a pH value that is not too low, i.e., below -1.5, preferably not below -1.75, more preferably not below -2, and most preferably not below -2.2, so that the composition can be used without extreme protective measures by those charged with handling and applying them to surfaces. The latter permits the acid to have sufficient oxidizing capacity to permit overcoming or avoid› ance of certain endospore defenses such as, for example, oxidation of disulfide linkages and protein polymers on the endospore coat, which allows the outer spore coat to be breached. 

[0072] Preferred pKa values are greater than -1, greater than -1.5, greater than -2, greater than -2.5, greater than -3, greater than -3.5, greater than -4, greater than -4.5, greater than -5, and even greater than -5.5. Acids with lower pKa values can be used if other steps are taken to ensure compliance with required or desired properties of the com› position such as pH range ( discussed above) and effective solute concentration ( discussed below). 0 

[0073] Preferred E red values are those which are at least +0.20 V, at least +0.25 V, at least +0.33 V, at least +0.40 V, at least +0.50 V, at least +0.60 V, at least +0.67 V, at least +0.75 V, at least +0.80 V, at least +0.90 V, at least +1.00 V, at least +1.10 V, at least +1.20 V, or even at least +1.25 V. 

[0074] Some oxidizing acids are not particularly stable in aqueous solutions. Accordingly, where a composition with an oxidizing acid is desired, preparing the oxidizing acid in vitro can be advantageous. For example, to a solvent com› ponent of a composition can be provided acetic acid and hydrogen peroxide which, when contacted, reversibly form peracetic acid. 

[0075] The amount of any given acid employed can be determined from the target pH of a given composition and the pKa value(s) of the chosen acids in view of the type and amounts of compound(s), if any, utilized to achieve the desired effective solute concentration in the composition. (More discussion of osmolarity and the types of osmolarity› adjusting compounds appears below.) 

[0076] Also present in the solute component of the com› position is an electrolyte oxidizing agent that does not contain any active hydrogen atoms when subjected to the Zerewitinoff determination. Non-limiting examples of potentially useful electrolyte, preferably inorganic, oxidiz› ing agents include compounds which include anions such as manganate, permanganate, peroxochromate, chromate, dichromate, peroxymonosulfate, and the like. (Some of these electrolytes can impact pH, so a composition formu› lated to have a given pH might require adjustment after addition of the oxidizing agent(s).) Preferred are those compounds having E 0 red values of at least + 1.25 V, prefer› ably at least +1.5 V, more preferably at least +1.75 V, even more preferably at least +2.0 V and most preferably at least +2.25 V. 

[0077] Electrolyte oxidizing agents generally can be added at up to their individual solubility limits, although the maximum amount generally is on the order of 30 g/L total 

