Compositions, Processes and Systems to Produce Hypochlorous Acid

Abstract

Hypochlorite salts and substantially dehydrated acid-form cation exchange resin beads are combined at specified ratios within a porous enclosure such as a pouch or sachet. Hypochlorous acid solutions are produced on demand by introducing the mixture-containing pouch into a chemical excess of water. Spontaneous exchange reactions occur at room temperature within a few minutes to produce aqueous hypochlorous acid, while the cations from the hypochlorite salt are simultaneously sequestered by the resin beads. The resin beads remain contained within the original porous enclosure to allow mechanical isolation or separation from the resulting solution.

Claims

1. A mixture of at least one hypochlorite salt containing hypochlorite ions; and at least one cation exchange resin in predominantly protonated (H+) form containing available protons; the salt and the resin in such proportion that the number of available protons contained in the resin is greater than 50% of the number of hypochlorite ions.

2. The mixture of claim 1, wherein said cation exchange resin comprises a material selected from the group consisting of crosslinked polymers of acrylic acid, crosslinked polymers of methacrylic acid, and sulfonated crosslinked polystyrene.

3. The mixture of claim 1, the salt and the resin in such proportion that the number of available protons contained in the resin is greater than 90% of the number of hypochlorite ions.

4. The mixture of claim 1, the salt and the resin in such proportion that the number of available protons contained in the resin is greater than 97% of the number of hypochlorite ions.

5. The mixture of claim 1, said resin dried to remove substantially all water therefrom.

6. The mixture of claim 1, the salt comprising granular commercial grade hypochlorite; said hypochlorite containing at least 65% by mass of free available chlorine; and the mixture comprising resin and salt in a mass ratio of at least about 5:1.

7. The mixture of claim 6, the mixture comprising resin and salt in a mass ratio of at least about 8:1.

8. The mixture of claim 1, further comprising water; the salt and resin in the water forming an aqueous mixture containing hypochlorous acid and at least one substantially insoluble cation exchange resin; said at least one substantially insoluble cation exchange resin being present in mixed cation form.

9. The mixture of claim 8, said mixed cation form comprising both protons and metal ions, the metal ions being of Group I or Group II.

10. The mixture of claim 8, said mixture having a pH of more than 3.5 and less than 7.4; and said mixture containing from 10 to 25,000 parts per million of free available chlorine.

11. The mixture of claim 10, said mixture having a pH of more than 5 and less than 6; and said mixture containing from 200 to 2000 parts per million of free available chlorine.

12. The mixture of claim 8, further comprising at least one solute; further comprising a sealed filter bag; said filter bag enclosing the salt and the resin within the filter bag; said filter bag retaining a substantial amount of the resin within said aqueous mixture; and said filter bag allowing the water, the aqueous solution, and the at least one solute to permeate therethrough.

13. The mixture of claim 1, the salt further comprising at least one inorganic salt selected from the group consisting of an alkali chloride, an alkali hydroxide, an alkaline earth chloride, and alkaline earth hydroxide.

14. The mixture of claim 1, said mixture also containing acidic components admixed therein to form an admixture; wherein said admixture is substantially stable over a period of at least about a year.

15. The mixture of claim 1, said hypochlorite salt comprising at least one hypochlorite selected from the group consisting of an alkali hypochlorite, a basic alkali hypochlorite, an alkaline earth hypochlorite, a basic alkaline earth hypochlorite, and a mixture of any of these above hypochlorites.

16. A process for forming hypochlorous acid, comprising: combining a hypochlorite salt containing hypochlorite ions, at least one cation exchange resin in predominantly protonated (H+) form containing available protons, and water; and said combining step comprising combining said salt and said resin in such portions that the available protons are sufficient to protonate at least 50% of the hypochlorite ions; and allowing said mixture to spontaneously react for a period of 1 minute or longer.

17. The process of claim 16, further providing a container or vessel with at least one opening through which the various said components may be introduced and/or removed, and allowing said spontaneous reaction to happen within said container or vessel.

18. The process of claim 16, further comprising: introducing the hypochlorite salt and the at least one cation exchange resin into a container having at least one opening; and after the allowing step, removing protonated hypochlorite ions from said container through the at least one opening.

19. The process of claim 16, said combining step comprising combining said salt and said resin in such portions that the available protons are sufficient to protonate at least 90% of the hypochlorite ions.

20. The process of claim 16, said combining step comprising combining said salt and said resin in such portions that the available protons are sufficient to protonate at least 97% of the hypochlorite ions.

22. The process of claim 16, further comprising removing at least a portion of the insoluble solids from the mixture.

23. The process of claim 16, further comprising, prior to the combining step, drying said resin to remove substantially all water therefrom.

24. The process of claim 16, wherein, after the allowing step, the mixture has a pH of more than 3.5 and less than 7.4 and contains from 10 to 25,000 parts per million of free available chlorine.

25. The process of claim 16, further comprising: before the combining step, enclosing the hypochlorite salt and the at least one cation exchange resin in a filter bag; and allowing the water to permeate through the filter bag to mix with the hypochlorite salt and the at least one cation exchange resin.

26. A system to produce hypochlorous acid, comprising: a water permeable filter bag; and a load, the load comprising at least one hypochlorite salt containing hypochlorite ions; and at least one cation exchange resin in predominantly protonated (H+) form containing available protons; the salt and the resin in such proportion that the number of available protons contained in the resin is greater than 50% of the number of hypochlorite ions.

27. The system of claim 26, the filter bag comprising a synthetic polymer; and the filter bag having an effective US mesh size of greater than or equal to 50.

28. The system of claim 26, further comprising a protective package; said protective package holding the filter bag within.

29. The system of claim 28, further comprising a dessicant within said protective package.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0024] FIG. 1 shows steps of a process for carrying out an embodiment of the invention.

[0025] FIG. 2 shows steps of a process for carrying out an embodiment of the invention.

[0026] FIG. 3A is a front view of an embodiment of the invention.

[0027] FIG. 3B is a partial cutaway side view of the device in FIG. 3A.

DETAILED DESCRIPTION OF THE INVENTION

[0028] For purposes of illustration, and without claiming to address all species potentially present, we indicate here the spontaneous chemical reactions that occur when said HTH granules, resin, and water are combined according to the present invention.

[0029] From minerals in water plus carbon dioxide (hardness of source water):

[0030] Mg(OH).sub.2+CO.sub.2.fwdarw.Mg.sup.2+ (aq)+2 HCO.sub.3.sup.−(aq) and

[0031] Ca(OH).sub.2+CO.sub.2.fwdarw.Ca.sup.2+ (aq)+2 HCO.sub.3.sup.−(aq)

[0032] From HTH+water (HTH granule dissolution):

[0033] Ca(OCl).sub.2 (s).fwdarw.Ca.sup.2+ (aq)+2 OCl.sup.−(aq) and

[0034] CaCl.sub.2 (s).fwdarw.Ca.sup.2+ (aq)+2 Cl.sup.−(aq) and

[0035] NaCl(s).fwdarw.Na.sup.+ (aq)+Cl.sup.− (aq) and

[0036] Ca(OH).sub.2 (s).fwdarw.Ca(OH).sub.2 suspension

[0037] From HTH+water+Acid form resin (spontaneous reactions enabling an embodiment of the invention):

[0038] Hardness reducing:

[0039] Mg.sup.2+ (aq)+2 HCO.sub.3.sup.−(aq)+2 R—COOH.fwdarw.(RCOO—).sub.2 Mg.sup.2+ (s)+H.sub.2O (1)+CO.sub.2 (g)

[0040] Ca.sup.2+ (aq)+2 HCO.sub.3.sup.−(aq)+2 R—COOH.fwdarw.(RCOO.sup.−).sub.2 Ca.sup.2+ (s)+H.sub.2O (1)+CO.sub.2 (g)

[0041] Neutralizing suspended Ca(OH).sub.2:

[0042] Ca(OH).sub.2+2 RCOOH.fwdarw.(RCOO.sup.−).sub.2 Ca.sup.2+ (s)+2 H.sub.2O (1)

[0043] Ion exchange:

[0044] 2 RCOOH+Ca.sup.2+ (aq)+2 OCl.sup.− (aq).fwdarw.(RCOO.sup.−).sub.2 Ca.sup.2+(s)+2 HOCl (aq)

[0045] The driving forces for these spontaneous chemical reactions are the solvation energies of the various ions, the strong basicity of the hydroxide ion (pK.sub.a=14), the relatively weak acidity of the hypochlorite ion (pK.sub.a=7.46) and the acidity of the ion exchange resin (pK.sub.a˜4.75 for weak acid cation exchange resins). Thus, when the solution pH is 7.46, 50% of the hypochlorite ions are protonated as a result of the equilibrium balance of chemical forces in the solution. In this instance, H.sup.+ will transfer from the resin to the OCl.sup.− ions because there is 2.71 units of difference, or around a factor of about 500 in favor of the HOCl+Resin-M.sup.n+ reaction. Thus, it will be recognized by those skilled in the art that aforementioned reactions are generally spontaneous due to energy considerations and accompanied by relatively rapid kinetics. After mixing and reaction, at least as much as 50%, 80%, 90%, 95% or 97% of the hypochlorite ion is protonated and present as hypochlorous acid. Therefore, the desired hypochlorous acid solutions may be realized spontaneously within a short period of time by combining the components of the present invention.

[0046] Said resin and its counterions, above denoted [(RCOO.sup.−).sub.2M.sup.2+ (s)] may be removed from the solution once the said spontaneous chemical reactions are substantially complete, for example, by decantation, filtration, or other process as may cause the liquid and solid present in the resin-salt reaction mixture to separate. The system may optionally contain a filtration device, such as a woven or patterned filter or filter membrane fabricated from common materials such as nylon, polyester, polytetrafluoroethylene, polyethylene, polypropylene, and the like. The resin materials may be stored in the described system encased in such a polymer fabric in order to form a filter bag to facilitate removal of the resin containing metal salt once the reaction providing hypochlorous acid is substantially complete.

[0047] In an embodiment, one may create an acid production system by enclosing a load of both the dry hypochlorite salt and the dry resin within the same packet or sachet (or filter bag). Then one may immerse in water said packet or sachet, preferably constructed from polyester mesh fabric. The dry hypochlorite salt dissolves in the water providing a hypochlorite solution, and the acid-form ion exchange resin then undergoes ion-exchange reactions with the solution, providing the hypochlorous acid solution and polymer-bound metal cations. These processes and reactions may be accelerated by shaking, stirring, or other agitation to assist principally in the dissolution of the hypochlorite salt. Finally, optionally, the packet or sachet can be removed from the solution produced, removing all or substantially all of the resin and the cations now bound thereto.

[0048] A polyester ‘screen print mesh’ fabric may be used. This is a fabric made from single thread polyester woven into a tight weave with very small pores that is nonetheless allows rapid penetration of water through the pores. The sachet may be formed of the mesh fabric, filled with the dry hypochlorite salt and the dry resin, and the sealed, such as with an impulse sealer. In commerce, the sizes of these pores are standardized and the fabrics are numbered according to the standard US Mesh sizes. The mesh value may be chosen to result in a pore size smaller than the smallest expected bead of the ion exchange resin. For example, some of the resins mentioned above are provided with a particle size range of, for instance 16-50 Mesh. Therefore, choosing a polyester screen print fabric with a higher mesh value (smaller pore size) is preferred in order to facilitate physical sequestration of the ion exchange resin to a small volume of the solution while allowing rapid and free molecular level exchange with the solution, and such sequestration serves to ease the removal of the resin particles from the solution once the desired final conditions of HOCl concentration are reached, simultaneously removing a large fraction of cations contributed by the dry high test hypochlorite. In this manner, the final HOCl solution produced has a much lower level of total dissolved solids (TDS) than can be produced, for instance, by electrolysis of metal chloride solutions.

[0049] Referring to FIGS. 2A & 2B, in an embodiment of the invention, acid production system 1 includes sachet 10 (filter bag) and load 20. Sachet 10 is formed of mesh fabric 11 including pores 12. Sachet 10 has seal 14, which closes an opening used to fill sachet 10 with load 20 to preclude load 20 from escaping therefrom. Load 20 includes resin 21 and hypochlorite salt 22.

[0050] In an embodiment, the composition, process, and system provide the ability to generate hypochlorous acid on demand at a location where weight transport is at a premium. At typical application dilutions of hypochlorous acid, the overwhelming majority, greater than 99%, 99.5%, or even 99.95% of the solution is water.

[0051] As hypochlorous acid is an effective biocide and disinfectant, many even non-potable or stagnant water sources may be envisioned as suitable for use with embodiments of the invention, as long as sufficient hypochlorous acid concentration is achieved to effectively reduce the biohazard to an acceptable level. This is advantageous over other forms of hypochlorite/hypochlorous acid, peroxide, and other biocides that must be transported as solutions.

[0052] Additionally, embodiments of the invention may be built at a size suited for the intended use. A small system may be used by one or a few individuals, while a large system could provide hypochlorous acid suitable for many users on either a batch or continuous flow basis. In other embodiments, a container or vessel for carrying out any of the disclosed processes may be provide and used for that process. Such a container or vessel would have at least one opening through which the various dry and wet components of the invention may be introduced and removed.

[0053] In embodiments of the invention, the components can be designed to be disposable or recyclable, as resources may allow. The acid-form of the resin, H.sup.+-Resin, may be regenerated by treating the metal-form of the resin, M.sup.n+-Resin with a suitable aqueous acid, such as dilute acetic acid, dilute hydrochloric acid, etc. In this manner, the system of the present invention may alternately be fed by hypochlorite salt solutions, to generate hypochlorous acid, followed by water to remove residual hypochlorous acid, followed by acid to regenerate the resin, followed by water to remove residual acid, and the cycle repeated. The scale on which this exchange may be effected may be very small (g scale) or very large (ton scale, as in a water treatment plant or similar industrial installation).

[0054] Resin manufacturers often note that combination of ion exchange resins with oxidizing agents such as nitrates should be avoided due to uncontrollable reaction of the nitric acid thus formed with the benzene rings available on the resin. However, this limitation typically applies to strong acid cation resins, those containing sulfonated polystyrene and similar chemicals, which can undergo nitration reactions. With the weak acid cation resins, there are many fewer benzene rings present (due only to the cross-linking divinylbenzene component of the resin), as they may or may not be present on the crosslinker, but typically not on the polymer backbone. A mild discoloration of the ion exchange resin when contacted with concentrated hypochlorite salt solutions may occur, but strong evolution of heat is avoided. In particular, temperatures were not seen to increase substantially.

[0055] A further distinction is that, in the case of a weak acid ion exchange resin, only a weak organic acid, pKa˜5, is available for reaction with the hypochlorite salt and any spectator salts. Therefore, while a strong acid cation resin, a common type of ion exchange resin used in water softening, may be employed, said strong acid resins are less applicable because they may result in pH values substantially lower than the preferred range of pH 4-7.

[0056] Mixtures of resins of various types are also operable. For instance, a mixture of a strong acid cation H-form resin and a weak acid cation salt form, e.g., Na+-form resin practically provide a buffered weak form cation resin once contacted with water. Thus, various mixtures of weak- and strong-form resins such as these are contemplated in embodiment of the invention. One could formulate a mixture of such resins which effectively performs similar functions, but has advantages of cost, availability, etc. depending on prevailing commercial conditions or other consideration. In another embodiment, a dry acid (such as tartaric, citric) is mixed with the other dry components (a Na+ resin and hypochlorite salt). In this embodiment, the dry acid, the resin, and the hypochlorite salt would be used to combine in an aqueous solution to form hypochlorous acid and a mixture of metal-ion form resin and metal-ion salt of the acid, which might itself be barely soluble or even insoluble in the final mixture. While not a preferred embodiment of the invention, such mixtures are operable within the context and spirit of the instant invention.

[0057] As noted above, the control of the pH of the resulting solution is due to the masses of hypochlorite salt and weak acid cation exchange resin mixed in the process or system. Typically the conditions are selected so that there is an excess of ion-exchange resin H.sup.+ sites, from 50% to 5000%, and preferably from 400% to 900% or from 600% to 900%. In this manner, the pH of the water used, from natural, commercial, or utility sources, does not play a strong role in the pH of the final composition, rather by the concentration of hypochlorite salt and H.sup.+-resin. If excess hypochlorite salt were present, the pH of the resulting mixture would likely exceed 7.5, where over half the hypochlorite ions would be present in ionized form. Therefore it is important to use a suitable excess of H.sup.+-form resin. Providing excess resin also assists in ensuring quick reaction times once mixed with water, and by diluting the fraction of hypochlorite in the dry mixture, thus rendering that mixture safer to handle. When employing the preferred weak acid cation resin in H-form, even excess resin will not cause over-acidification of the solution; only salts of weak acids will be protonated under the conditions of use of the compositions, processes, and systems. The typical pH of a resulting solution is preferably between about 2.25 and 7, or about 3.5 and 7.4, or about 3.5 and 8.0, even more preferably between 3.5 and 6.5, and even more preferably between 5 and 6. In particular embodiments, the process can include combining the salt and the resin in such portions that the available protons are sufficient to protonate at least 50%, at least 90%, or at least 97% of the hypochlorite ions.

[0058] In sum, this invention: 1) provides for the dry transportation of an equivalent of hypochlorous acid; 2) substantially lessens concerns regarding the stability of hypochlorous acid in solution by providing a means of preparation anywhere water is available; 3) controls the final pH of the solution to a regime where the majority of hypochlorite species are present as hypochlorous acid; 4) with suitable compositions, dramatically lessens the soluble compounds such as sodium chloride, calcium chloride, hydrochloric acid, molecular chlorine (Cl.sub.2), salts of isocyanuric acid, buffering agents, and other undesirable byproducts produced by alternative compositions, processes, and systems.

EXAMPLES

[0059] We have found that solutions of hypochlorous acid in a suitable range of pH may be generated by treatment of dilute alkali and alkaline earth hypochlorites with such H.sup.+-form ion exchange resins. The dilute solutions of HOCl thus produced, in the range from 200-2000 ppm free available chlorine (FAC) are largely colorless and contain much lower concentrations of other ionic species, 1-2 orders of magnitude less than the electrolytic solutions of hypochlorous acid formed from sodium chloride solutions. The counterions, typically calcium, of the hypochlorite are removed from the solution by the ion exchange mechanism. By removing the ion exchange resin, typically in the form of a gel or small beads, a more pure and useful solution results. The following examples are illustrative.

Example 1

[0060] 1.0 g of HTH Calcium hypochlorite granules, (min FAC 70%), was dissolved in 250 cc of water from the local municipal supply by shaking for 5 minutes. A pale milky white mixture resulted, revealing the presence of Ca(OH)2 in suspension. The pH measured by electrode was ˜12 and the ORP was ˜500 mV. 3 grams of H+-form weak acid ion exchange resin Amberlite CG50 was added at once, and the mixture shaken for two minutes. The ion exchange resin was allowed to settle, and the solution decanted. The principal solute was hypochlorous acid. The pH of the clear resulting solution was 6.0 and the ORP 1025 mV. At pH 6.0 approximately 97% of the hypochlorite ion is protonated and present as hypochlorous acid. The FAC was tested with a test strip and registered over 2,000 ppm. The solution was diluted to 1 gallon with additional municipal water, and tested again. The pH was 6.1 and the FAC was over 200 ppm.

Example 2

[0061] 1.0 g of HTH Calcium hypochlorite granules, (min FAC 70%), was admixed with 3 g of H+-form weak acid ion exchange resin Amberlite CG50 in a closed Nalgene 500 cc bottle for 1 week. No gas evolution, color change, or odor increase was noted. 250 cc of municipal supply water was added and the mixture shaken for 5 minutes. The ion exchange resin was allowed to settle. The solid comprised excess H.sup.+-form resin as well as a lesser amount of M.sup.n+ form resin. The pH of the clear resulting solution was 6.2 and the ORP 1001 mV. The FAC was tested with a test strip and registered over 2,000 ppm. The solution was diluted to 1 gallon with additional municipal water, and tested again. The pH was 6.1 and the FAC was over 200 ppm.

Example 3

[0062] 1.0 g of HTH Calcium hypochlorite granules, (min FAC 70%), was dissolved in 250 cc of water from the local municipal supply by shaking for 5 minutes. A pale milky white mixture resulted, revealing the presence of lime (Ca(OH).sub.2) in suspension. The pH measured by electrode was ˜12 and the ORP was ˜500 mV. 10 grams of H+-form weak acid ion exchange resin Amberlite MAC-3H (supplied as 50% resin/50% water by weight) was added at once, and the mixture shaken for two minutes. The ion exchange resin was allowed to settle, and the solution decanted. The pH of the clear resulting solution was 6.0 and the ORP 1006 mV. At pH 6.0 approximately 97% of the hypochlorite ion is protonated and present as hypochlorous acid. The FAC was tested with a test strip and registered over 2,000 ppm. The solution was diluted to 1 gallon with additional municipal water, and tested again. The pH was 6.1 and the FAC was over 200 ppm.

Example 4

[0063] 109.44 g of Amberlite MAC-3H ion exchange resin was dried in an oven under air at 107° C. for 12 hours. The resulting dry solid weighed 55.80 g, suggesting a water content of 49% in the as-received resin. 1.0 g of HTH Calcium hypochlorite granules, (min FAC 70%), was dissolved in 250 cc of water from the local municipal supply by shaking for 5 minutes. A pale milky white mixture resulted, revealing the presence of lime (Ca(OH).sub.2) in suspension. The pH measured by electrode was ˜12 and the ORP was ˜500 mV. 5 grams of the dried H.sup.+-form weak acid ion exchange resin Amberlite MAC-3H was added at once, and the mixture shaken for 15 minutes. The ion exchange resin was allowed to settle, and the solution decanted. The pH of the clear resulting solution was 5.9 and the ORP 1020 mV. The FAC was tested with a test strip and registered over 2,000 ppm. The solution was diluted to 1 gallon with additional municipal water, and tested again. The pH was 6.1 and the FAC was over 200 ppm.

Example 5

[0064] 50.0 g of the dried resin of example 4 was admixed with 10 grams of HTH Calcium hypochlorite granules, (min FAC 70%), and this mixture allowed to stand for several days at room temperature in a closed Nalgene bottle. No evolution of gas, discoloration, or increase in odor was noted.

Example 6

[0065] 10 g of a sulfonic acid ion exchange resin were treated with 50 cc of 3N HCl, filtered, and thoroughly rinsed with water until the rinse pH was neutral. 1.0 g of HTH Calcium hypochlorite granules, (min FAC 70%), was dissolved in 250 cc of water from the local municipal supply by shaking for 5 minutes. A pale milky white mixture resulted, revealing the presence of lime (Ca(OH).sub.2)in suspension. The pH measured by electrode was ˜12 and the ORP was ˜500 mV. The strong acid cation exchange resin was added at once and the mixture swirled for a few seconds. The pH was 4 and the ORP was 1075 mV. This mixture was decanted from the resin beads and diluted to 1 gallon with municipal water. The pH was 6.4 and the ORP was 975 mV.

Example 7

[0066] With reference to FIG. 2, in step 100, a sachet was constructed from 180 mesh polyester screen print fabric by sealing all but one side with an impulse sealer, leaving an opening on one side. Next in step 110, 10 g of the dried MAC3-H resin from example 4, was introduced to the sachet, followed by step 120 which introduced 1 g of HTH Calcium hypochlorite granules, (min FAC 70%). The resin and granules were sealed inside the sachet with the impulse sealer in step 130. Step 140 was skipped. In step 150, the sachet was introduced to 1 pint of distilled water and allowed to stand for 15 minutes in step 160, thus permitting water to enter the sachet through pores in the material and mix with the HTH and resin. At step 170, the process is complete. The solution was diluted to 1 gallon and tested for FAC. The level of FAC was approximately 200 ppm as determined by a commercial FAC test strip.

Example 8

[0067] Again with reference to FIG. 1 and example 7, a sachet similar to that of example 7 was constructed by following steps 100, 110, 120, and 130. The sachet was then allowed to age under room conditions for several weeks (step 140). The immersion process into one gallon of water, step 150, was then conducted, followed by step 160, where spontaneous chemical reactions were allowed to proceed. At step 170, the process is complete. The FAC was measured at 200 ppm with a commercial FAC test strip.

Example 9

[0068] With reference to FIG. 2, in step 200, a container is provided for the resin and salts. Next in step 210, dried resin is introduced to the container, followed by step 220 in which HTH is added to the container. In step 225, the HTH and dried resin are mixed in the container. In step 240 an optional waiting period is observed. In step 250, water is introduced into the container, permitting water to mix with the resin and HTH. In step 260, a waiting period of at least 1 minute is observed. At step 270 the process is complete.

[0069] The foregoing examples show in many respects different aspects of the instant invention which are itemized in the claims below. They show a ready, flexible, scalable, and economic method of generating a consistent and predictable solution of hypochlorous acid from solid precursors which additionally features much lower concentrations of spectator ions than competing methods. This solution of hypochlorous acid may find uses in human and animal medicine, general cleaning, flower preservation, antimicrobial treatments and many other uses where the advantages of hypochlorous acid are known.