Hypochlorous acid
578099
221282095
2008-06-23T21:05:07Z
134.84.206.60
fixed consistent misspelling of sulfhydryl from "sulfhydral"
{{Chembox new
| Name = Chloric(I) acid
| ImageFile = Hypochlorous-acid-2D-dimensions.png
| ImageSize = 150px
| ImageName = Chloric(I) acid
| ImageFile1 = Hypochlorous-acid-3D-vdW.png
| ImageSize1 = 150px
| ImageName1 = Chloric(I) acid
| IUPACName = chloric(I) acid
| OtherNames = hydrogen hypochlorite<br />hydrogen chlorate(I)<br />hypochlorous acid
| Section1 = {{Chembox Identifiers
| SMILES = HClO
| CASNo = 7790-92-3
| EINECS = 232-232-5
| RTECS =
}}
| Section2 = {{Chembox Properties
| Formula = HClO
| MolarMass = 52.46 g/mol
| Appearance = colorless aqueous solns
| Density = ? g/cm<sup>3</sup>, ?
| Solubility = soluble
| MeltingPt = (? K)
| BoilingPt = °C (? K)
| pKa = 7.497<ref name=ref1>Morris, J. C. 1966. The acid ionization constant of HOCl from 5 to 35 °. J. Phys. Chem. 70:3798-3805.</ref>
}}
| Section3 = {{Chembox Structure
| Dipole =
}}
| Section7 = {{Chembox Hazards
| MainHazards = oxidizer
| RPhrases =
| SPhrases =
}}
| Section8 = {{Chembox Related
| OtherAnions =
| OtherCations =
| OtherCpds = Cl<sub>2</sub><br />[[Calcium hypochlorite|Ca(OCl)<sub>2</sub>]]
[[sodium hypochlorite|NaOCl]]
}}
}}
'''Hypochlorous acid''' ([[IUPAC]] name '''chloric(I) acid''') is a weak [[acid]] with the [[chemical formula]] HClO. It forms when [[chlorine]] dissolves in water. It cannot be isolated in pure form due to rapid equilibration with its precursor (see below). HClO is used as a [[Bleach (chemical)|bleach]], an [[oxidation|oxidizer]], a [[deodorant]], and a [[disinfectant]].
==Formation==
Addition of [[chlorine]] to [[water]] gives both chloric(I) acid and [[hydrochloric acid]]<ref name=ref2>Fair, G. M., J. C. Morris, S. L. Chang, I. Weil, and R. P. Burden. 1948. The behavior of chlorine as a water disinfectant. J. Am. Water Works Assoc. 40:1051-1061.</ref> (HCl):
:Cl<sub>2</sub> + H<sub>2</sub>O → HOCl + HCl
==Uses==
In [[organic synthesis]], HOCl converts [[alkene]]s to [[chlorohydrin]]s.<ref> Unangst, P. C. "Hypochlorous Acid" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. DOI: 10.1002/047084289.</ref>
In [[biology]], hypochlorous acid is generated in activated [[neutrophil]]s by myeloperoxidase mediated peroxidation of chloride ions, and contributes to the destruction of [[bacteria]].<ref>Harrison, J. E., and J. Schultz. 1976. Studies on the chlorinating activity of myeloperoxidase. Journal of Biological Chemistry volume 251, pages1371-1374.</ref><ref name=ref93>Thomas, E. L. 1979. Myeloperoxidase, hydrogen peroxide, chloride antimicrobial system: Nitrogen-chlorine derivatives of bacterial components in bactericidal action against ''Escherichia coli''. Infect. Immun. 23:522-531.</ref><ref name=ref3/>
Hypochlorous acid is the active sanitizer in hypochlorite based swimming pool products.
==Chemical reactions==
In [[water|aqueous]] solution, hypochlorous acid partially dissociates into the anion ''hypochlorite'' ClO<sup>-</sup>:
:HOCl<math>\overrightarrow{\leftarrow}</math> OCl<sup>-</sup> + H<sup>+</sup>
[[salt (chemistry)|Salt]]s of hypochlorous acid are also called '''hypochlorites'''. One of the best known hypochlorites is [[sodium hypochlorite|NaOCl]], the active ingredient in bleach.
In the presence of sunlight, hypochlorous acid decomposes into [[hydrochloric acid]] and [[oxygen]], so this reaction is sometimes seen as:
:2Cl<sub>2</sub> + 2H<sub>2</sub>O → 4HCl + O<sub>2</sub>
HOCl is considered to be a stronger oxidant than chlorine.
HOCl reacts with HCl to form chlorine gas:
HOCl + HCl → H<sub>2</sub>O + Cl<sub>2</sub>
===Reactivity of HOCl with biomolecules===
Hypochlorous acid reacts with a wide variety of biomolecules including DNA, RNA,<ref name=ref3>Albrich, J. M., C. A. McCarthy, and J. K. Hurst. 1981. Biological reactivity of hypochlorous acid: Implications for microbicidal mechanisms of leukocyte myeloperoxidase. Proc. Natl. Acad. Sci. USA 78:210-214.</ref><ref name=ref21>Dennis, W. H., Jr, V. P. Olivieri, and C. W. Krusé. 1979. The reaction of nucleotides with aqueous hypochlorous acid. Water Res. 13:357-362.</ref><ref name=ref45>Jacangelo, J. G., and V. P. Olivieri. 1984. Aspects of the mode of action of monochloramine. In R. L. Jolley, R. J. Bull, W. P. Davis, S. Katz, M. H. Roberts, Jr., and V. A. Jacobs (ed.), Water Chlorination, vol. 5. Lewis Publishers, Inc., Williamsburg.</ref><ref name=ref69>Prütz, W. A. 1998. Interactions of hypochlorous acid with pyrimidine nucleotides, and secondary reactions of chlorinated pyrimidines with GSH, NADPH, and other substrates. Arch. Biochem. Biophys. 349:183-191.</ref> fatty acid groups, cholesterol<ref name=ref7>Arnhold, J., O. M. Panasenko, J. Schiller, Y. A. Vladimirov, and K. Arnold. 1995. The action of hypochlorous acid on phosphatidylcholine liposomes in dependence on the content of double bonds. Stoichiometry and NMR analysis. Chem. Phys. Lipids 78:55-64.</ref><ref name=ref16>Carr, A. C., J. V. D. Berg, and C. C. Winterbourn. 1996. Chlorination of cholesterol in cell membranes by hypochlorous acid. Arch. Biochem. Biophys. 332:63-69.</ref><ref name=ref23>Domigan, N. M., M. C. M. Vissers, and C. C. Winterbourn. 1997. Modification of red cell membrane lipids by hypochlorous acid and haemolysis by preformed lipid chlorhydrins. Redox Rep. 3:263-271.</ref><ref name=ref37>Hazell, L. J., J. V. D. Berg, and R. Stocker. 1994. Oxidation of low density lipoprotein by hypochlorite causes aggregation that is mediated by modification of lysine residues rather than lipid oxidation. Biochem. J. 302:297-304.</ref><ref name=ref39>Hazen, S. L., F. F. Hsu, K. Duffin, and J. W. Heinicke. 1996. Molecular chlorine generated by the myeloperoxidase-hydrogen peroxide-chloride system of phagocytes converts low density lipoprotein cholesterol into a family of chlorinated sterols. J. Biol. Chem. 271:23080-23088.</ref><ref name=ref97>Vissers, M. C. M., A. C. Carr, and A. L. P. Chapman. 1998. Comparison of human red cell lysis by hypochlorous acid and hypobromous acids: insights into the mechanism. Biochem. J. 330:131-138.</ref><ref name=ref98>Vissers, M. C. M., A. Stern, F. Kuypers, J. V. D. Berg, and C. C. Winterbourn. 1994. Membrane changes associated with lysis of red blood cells by hypochlorous acid. Free Rad. Biol. Med. 16:703-712.</ref><ref name=ref104>Winterbourne, C. C., J. V. D. Berg, E. Roitman, and F. A. Kuypers. 1992. Chlorhydrin formation from unsaturated fatty acids reacted with hypochlorous acid. Arch. Biochem. Biophys. 296:547-555.</ref> and proteins.<ref name=ref2>Albrich, J. M., and J. K. Hurst. 1982. Oxidative inactivation of Escherichia coli by hypochlorous acid. FEBS Lett. 144:157-161.</ref><ref name=ref9>Barrette, W. C., Jr., D. M. Hannum, W. D. Wheeler, and J. K. Hurst. 1989. General mechanism for the bacterial toxicity of hypochlorous acid: Abolition of ATP production. Biochemistry 28:9172-9178.</ref><ref name=ref37/><ref name=ref46>Jacangelo, J. G., V. P. Olivieri, and K. Kawata. 1987. Oxidation of sulfhydryl groups by monochloramine. Water Res. 21:1339-1344.</ref><ref name=ref48>Knox, W. E., P. K. Stumpf, D. E. Green, and V. H. Auerbach. 1948. The inhibition of sulfhydryl enzymes as the basis of the bactericidal action of chlorine. J. Bacteriol. 55:451-458.</ref><ref name=ref99>Vissers, M. C. M., and C. C. Winterbourne. 1991. Oxidative Damage to Fibronectin. Arch. Biochem. Biophys. 285:53-59.</ref><ref name=ref103>Winterbourne, C. C. 1985. Comparative reactivities of various biological compounds with myeloperoxidase-hydrogen peroxide-chloride, and similarity to the oxidant to hypochlorite. Biochim. Biophys. Acta 840:204-210.</ref>
====Reaction with protein sulfhydryl groups====
Knox et al.<ref name=ref48/> first noted that HOCl was a [[thiol|sulfhydryl]] inhibitor that in sufficient quantity could completely inactivate proteins containing [[thiol|sulfhydryl groups]]. This is because, HOCl oxidises [[thiol|sulfhydryl groups]] leading to the formation of [[disulfide bond]]s<ref name=ref67>Pereira, W. E., Y. Hoyano, R. E. Summons, V. A. Bacon, and A. M. Duffield. 1973. Chlorination studies: II. The reaction of aqueous hypochlorous acid with a - amino acids and dipeptides. Biochim. Biophys. Acta 313:170-180.</ref> that can result in crosslinking of [[protein]]s. The HOCl mechanism of [[thiol|sulfhydryl]] oxidation is similar to that of [[chloramine]], and may only be bacteriostatic, because once the residual chlorine is dissipated, some [[thiol|sulfhydryl]] function can be restored.<ref name=ref46/> One [[thiol|sulfhydryl]] containing amino acid can scavenge up to four molecules of HOCl.<ref name=ref103/> Consistent with this, it has been proposed that [[thiol|sulfhydryl groups]] of sulfur containing [[amino acid]]s can be oxidized a total of three times by three HOCl molecules, with the fourth reacting with the α-amino group. The first reaction yields [[sulfenic acid]] (R-SOH) then [[sulfinic acid]] (R-SO<sub>2</sub>H) and finally R-SO<sub>3</sub>H. Each of those intermediates can also condense with another [[thiol|sulfhydryl group]] causing cross linking and aggregation of proteins. [[Sulfinic acid]] and R-SO<sub>3</sub>H derivatives are only produced at high molar excesses of HOCl, and disulfides are primarily formed at bacteriocidal levels.<ref name=ref69/> Disulfide bonds can also be oxidized by HOCl to sulfinic acid.<ref name=ref67/> Because the oxidation of [[thiol|sulfhydryls]] and [[disulfide bond|disulfides]] evolves [[hydrochloric acid]],<ref name=ref69/> this process results in the depletion HOCl.
====Reaction with protein amino groups====
Hypochlorous acid reacts readily with amino acids that have [[amine|amino group]] side chains, with the chlorine from HOCl displacing a hydrogen resulting in an organic chloramine.<ref name=ref27>Dychdala, G. R. 1991. Chlorine and chlorine compounds, p. 131-151. In S. S. Block (ed.), Disinfection, Sterilization and Preservation. Lea & Febiger, Philadelphia.</ref> Chlorinated [[amino acid]]s rapidly decompose but [[protein]] chloramines are longer lived and retain some oxidative capacity.<ref name=ref103/><ref name=ref93/> Thomas et al.<ref name=ref93/> concluded from their results that most organic chloramines decayed by internal rearrangement and that fewer available [[amine|NH<small>2</small>]] groups promoted attack on the [[peptide bond]] resulting in cleavage of the [[protein]]. McKenna and Davies<ref name=ref60>McKenna, S. M., and K. J. A. Davies. 1988. The inhibition of bacterial growth by hypochlorous acid: possible role in the bactericidal activity of phagocytes. Biochem. J. 254:685-692.</ref> found that 10 mM or greater HOCl was necessary to fragment proteins in vivo. Consistent with these results it was later proposed that the chloramine undergoes a molecular rearrangement releasing [[HCl]] and [[ammonia]] to form an [[amide]].<ref name=ref38>Hazen, S. L., A. d'Avignon, M. M. Anderson, F. F. Hsu, and J. W. Heinicke. 1998. Human neutrophils employ the myeloperoxidase-hydrogen peroxide-chloride system to oxidize α-amino acids to a family of reactive aldehydes. J. Biol. Chem. 273:4997-5005.</ref> The [[amide group]] can further react with another [[amine|amino group]] to form a [[Schiff base]] causing cross linking and aggregation of proteins.<ref name=ref37/>
====Reaction with DNA and Nucleotides====
Hypochlourous acid reacts slowly with DNA and RNA as well as all nucleotides in vitro.<ref name=ref21/><ref name=ref68>Prütz, W. A. 1996. Hypochlorous acid interactions with thiols, nucleotides, DNA and other biological substrates. Arch. Biochem. Biophys. 332:110-120.</ref> [[guanosine monophosphate|GMP]] is the most reactive because HOCl reacts with both the heterocyclic NH group and the amino group. Similarly [[thymidine monophosphate|TMP]] with only a heterocyclic NH group that is reactive with HOCl is the second most reactive. [[adenosine monophosphate|AMP]] and [[cytidine monophosphate|CMP]] which only have a slowly reactive amino group are less reactive with HOCl.<ref name=ref68/> [[Uridine monophosphate|UMP]] has been reported to be reactive only at a very slow rate.<ref name=ref3/><ref name=ref21/> The heterocyclic NH groups are more reactive than amino groups and their secondary chloramines are able to donate the chlorine.<ref name=ref69/> These reactions likely interfere with DNA base pairing and consistent with this, Prütz<ref name=ref68/> has reported a decrease in viscosity of DNA exposed to HOCl similar to that seen with heat denaturation. The sugar moieties are unreactive and the DNA backbone is not broken.<ref name=ref68/> NADH can react with chlorinated TMP and UMP as well as HOCl. This reaction can regenerate UMP and TMP and results in the 5-hydroxy derivative of NADH. The reaction with TMP or UMP is slowly reversible to regenerate HOCl. A second slower reaction that results in cleavage of the pyridine ring occurs when excess HOCl is present. NAD+ is inert to HOCl.<ref name=ref68/><ref name=ref69/>
====Reaction with lipids====
Hypochlorous acid reacts with [[saturation|unsaturated bond]]s in [[lipid]]s, but not [[saturation|saturated bond]]s, and the [[hypochlorite|OCl<sup>−</sup>]] ion does not participate in this reaction. This reaction occurs by [[hydrolysis]] with addition of [[chlorine]] to one of the carbons and a [[hydroxyl]] to the other. The resulting compound is a chlorhydrin.<ref name=ref7/> The polar [[chlorine]] disrupts [[lipid bilayer]]s and could increase permeability.<ref name=ref16/> When chlorhydrin formation occurs in [[lipid bilayer]]s of red blood cells, increased permeability occurs. Disruption could occur if enough chlorhydrin is formed.<ref name=ref7/><ref name=ref98/> The addition of preformed chlorhydrins to [[red blood cell]]s can affect permeability as well.<ref name=ref23/> [[Cholesterol]] chlorhydrins have also been observed,<ref name=ref16/><ref name=ref39/> but do not greatly affect permeability, and it is believed that [[chlorine|Cl<sub>2</sub>]] is responsible for this reaction.<ref name=ref39/>
==Mode of disinfectant action==
''[[Escherichia coli]]'' exposed to hypochlorous acid lose [[viability]] in less than 100 ms due to inactivation of many vital systems.<ref name=ref2>Albrich, J. M., and J. K. Hurst. 1982. Oxidative inactivation of Escherichia coli by hypochlorous acid. FEBS Lett. 144:157-161.</ref><ref name=ref70>Rakita, R. M., B. R. Michel, and H. Rosen. 1990. Differential inactivation of Escherichia coli membrane dehydrogenases by a myeloperoxidase-mediated antimicrobial system. Biochemistry 29:1075-1080.</ref><ref name=ref71>Rakita, R. M., B. R. Michel, and H. Rosen. 1989. Myeloperoxidase-mediated inhibition of microbial respiration: Damage to Escherichia coli ubiquinol oxidase. Biochemistry 28:3031-3036.</ref><ref name=ref76>Rosen, H., and S. J. Klebanoff. 1985. Oxidation of microbial iron-sulfur centers by the myeloperoxidase-H2O2-halide antimicrobial system. Infect. Immun. 47:613-618.</ref><ref name=ref79>Rosen, H., R. M. Rakita, A. M. Waltersdorph, and S. J. Klebanoff. 1987. Myeloperoxidase-mediated damage to the succinate oxidase system of Escherichia coli. J. Biol. Chem. 242:15004-15010.</ref> Hypochlorous acid has a reported [[LD50|LD<sub>50</sub>]] of 0.0104 ppm - 0.156 ppm<ref name=ref17>Chesney, J. A., J. W. Eaton, and J. R. Mahoney, Jr. 1996. Bacterial glutathione: a sacrificial defense against chlorine compounds. J. Bacteriol. 178:2131-2135.</ref> and 2.6 ppm caused 100% growth inhibition in 5 minutes.<ref name=ref60/> However it should be noted that the concentration required for bactericidal activity is also highly dependent on bacterial concentration.<ref name=ref48/>
===Inhibition of glucose oxidation===
In 1948, Knox et al.<ref name=ref48/> proposed the idea that inhibition of [[glucose]] oxidation was a major factor in the bacteriocidal nature of chlorine solutions. He proposed that the active agent or agents diffused across the cytoplasmic membrane to inactivate key [[thiol|sulfhydryl]] containing [[enzyme]]s in the [[glycolysis|glycolytic pathway]]. This group was also the first to note that chlorine solutions (HOCl) inhibited [[Thiol|sulfhydryl]] [[enzyme]]s. Later studies have shown that at bacteriocidal levels, the [[cytosol]] components do not react with HOCl.<ref name=ref1/> In agreement with this, McFeters and Camper<ref name=ref59>McFeters, G. A., and A. K. Camper. 1983. Enumeration of indicator bacteria exposed to chlorine. Adv. Appl. Microbiol. 29:177-193.</ref> found that [[aldolase]], an [[enzyme]] that Knox et al.<ref name=ref48/> proposes would be inactivated, was unaffected by HOCl [[in vivo]]. It has been further shown that loss of [[thiol|sulfhydryl]]s does not correlate with inactivation.<ref name=ref46/> That leaves the question what causes inhibition of [[glucose]] oxidation. The discovery that HOCl blocks induction of [[β-galactosidase]] by added [[lactose]]<ref name=ref8>Barrette, W. C., Jr., J. M. Albrich, and J. K. Hurst. 1987. Hypochlorous acid-promoted loss of metabolic energy in Escherichia coli. Infect. Immun. 55:2518-2525.</ref> led to a possible answer to this question. The uptake of radiolabeled substrates by both ATP hydrolysis and proton co-transport may be blocked by exposure to HOCl preceding loss of viability.<ref name=ref1/> From this observation it proposed that HOCl blocks uptake of nutrients by inactivating transport proteins.<ref name=ref1/><ref name=ref9/><ref name=ref13>Camper, A. K., and G. A. McFeters. 1979. Chlorine injury and the enumeration of waterborne coliform bacteria. Appl. Environ. Microbiol. 37:633-641.</ref><ref name=ref59/> The question of loss of glucose oxidation has been further explored in terms of loss of respiration. Venkobachar et al.<ref name=ref96>Venkobachar, C., L. Iyengar, and A. V. S. P. Rao. 1975. Mechanism of disinfection. Water Res. 9:119-124.</ref> found that succinic dehydrogenase was inhibited in vitro by HOCl and this led to the investigation of the possibility that disruption of [[electron transport]] could be the cause of bacterial inactivation. Albrich et al.<ref name=ref3/> subsequently found that HOCl destroys [[cytochrome]]s and [[iron-sulfur cluster]]s and observed that oxygen uptake is abolished by HOCl and adenine nucleotides are lost. Also observed was, that irreversible oxidation of [[cytochrome]]s paralleled the loss of respiratory activity. One way of addressing the loss of oxygen uptake was by studying the effects of HOCl on succinate dependent [[electron transport]].<ref name=ref43>Hurst, J. L., W. C. Barrette, Jr., B. R. Michel, and H. Rosen. 1991. Hypochlorous acid and myeloperoxidase-catalyzed oxidation of [[iron-sulfur cluster]]s in bacterial respiratory dehydrogenases. Eur. J. Biochem. 202:1275-1282.</ref> Rosen et al.<ref name=ref79/> found that levels of reductable [[cytochrome]]s in HOCl treated cells were normal, and these cells were unable to reduce them. Succinate dehydrogenase was also inhibited by HOCl, stopping the flow of electrons to oxygen. Later studies<ref name=ref71/> revealed that Ubiquinol oxidase activity ceases first, and the still active [[cytochrome]]s reduce the remaining quinone. The [[cytochrome]]s then pass the [[electron]]s to [[oxygen]], which explains why the [[cytochrome]]s cannot be reoxidized as observed by Rosen et al.<ref name=ref79/> However, this line of inquiry was ended when Albrich et al.<ref name=ref2/> found that cellular inactivation precedes loss of respiration by using a flow mixing system that allowed evaluation of viability on much smaller time scales. This group found that cells capable of respiring could not divide after exposure to HOCl.
===Depletion of adenine nucleotides===
Having eliminated loss of respiration Albrich et al.<ref name=ref2/> proposes that the cause of death may be due to metabolic dysfunction caused by depletion of adenine nucleotides. Barrette et al.<ref name=ref8/> studied the loss of adenine nucleotides by studying the energy charge of HOCl exposed cells and found that cells exposed to HOCl were unable to step up their energy charge after addition of nutrients. The conclusion was that exposed cells have lost the ability to regulate their adenylate pool, based on the fact that metabolite uptake was only 45% deficient after exposure to HOCl and the observation that HOCl causes intracellular ATP hydrolysis. Also confirmed was; that at bacteriocidal levels of HOCl, cytosolic components are unaffected. So it was proposed that modification of some membrane bound protein results in extensive ATP hydrolysis, and this, coupled with the cells inability to remove AMP from the cytosol depresses metabolic function. One protein involved in loss of ability to regenerate ATP has been found to be [[ATP synthetase]].<ref name=ref9/> Much of this research on respiration reconfirms the observation that relevant bacteriocidal reactions take place at the cell membrane.<ref name=ref8/><ref name=ref9/><ref name=ref75>Rosen, H., and S. J. Klebanoff. 1982. Oxidation of Escherichia coli iron centers by myeloperoxidase-mediated microbicidal system. J. Biol. Chem. 257:13731-13735</ref>
===Inhibition of DNA replication===
Recently it has been proposed that bacterial inactivation by HOCl is the result of inhibition of [[DNA]] replication. When bacteria are exposed to HOCl there is a precipitous decline in [[DNA synthesis]] that precedes inhibition of [[protein]] synthesis, and closely parallels loss of viability.<ref name=ref60/><ref name=ref78>Rosen, H., J. Orman, R. M. Rakita, B. R. Michel, and D. R. VanDevanter. 1990. Loss of DNA-membrane interactions and cessation of DNA synthesis in myeloperoxidase-treated Escherichia coli. Proc. Natl. Acad. Sci. USA 87:10048-10052.</ref> During bacterial genome replication, the [[origin of replication]] (oriC in ''E. coli'') binds to proteins that are associated with the cell membrane, and it was observed that HOCl treatment decreases the affinity of extracted membranes for oriC, and this decreased affinity also parallels loss of viability. A study by Rosen et al<ref name=ref77>Rosen, H., B. R. Michel, D. R. vanDevanter, and J. P. Hughes. 1998. Differential effects of myeloperoxidase-derived oxidants on Escherichia coli DNA replication. Infect. Immun. 66:2655-2659.</ref> compared the rate of HOCl inhibition of DNA replication of plasmids with different replication origins and found that certain plasmids exhibited a delay in the inhibition of replication when compared to plasmids containing oriC. Rosen’s group proposed that inactivation of membrane proteins involved in DNA replication are the mechanism of action of HOCl.
==Safety==
HOCl is a strong oxidizer and can form explosive mixtures.
==External links==
* [http://www.npi.gov.au/database/substance-info/profiles/20.html National Pollutant Inventory - Chlorine]
==References==
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{{reflist}}
[[Category:Hypochlorites]]
[[Category:Acids]]
[[Category:Disinfectants]]
[[de:Hypochlorige Säure]]
[[fr:Acide hypochloreux]]
[[ko:하이포아염소산]]
[[it:Acido ipocloroso]]
[[hu:Hipoklórossav]]
[[nl:Waterstofhypochloriet]]
[[ja:次亜塩素酸]]
[[pl:Kwas chlorowy(I)]]
[[ru:Хлорноватистая кислота]]
[[sl:Hipoklorova kislina]]
[[sr:Хипохлораста киселина]]
[[uk:Гіпохлоритна кислота]]
[[zh:次氯酸]]