Abstract

The surgeon needs to have an inexpensive, available, nontoxic, and practical disinfectant that is effective in sanitizing against the COVID-19 (Coronavirus Disease 2019) virus. The purpose of this article was to review the evidence for using hypochlorous acid in the office setting on a daily basis. The method used to assemble recommendations was a review of the literature including evidence for this solution when used in different locations and industries other than the oral-maxillofacial clinic facility. The results indicate that this material can be used with a high predictability for disinfecting against the COVID-19 (Coronavirus Disease 2019) virus. The surgeon needs to have an inexpensive, available, nontoxic, and practical disinfectant that is effective in sanitizing against the COVID-19 (Coronavirus Disease 2019) virus. The purpose of this article was to review the evidence for using hypochlorous acid in the office setting on a daily basis. The method used to assemble recommendations was a review of the literature including evidence for this solution when used in different locations and industries other than the oral-maxillofacial clinic facility. The results indicate that this material can be used with a high predictability for disinfecting against the COVID-19 (Coronavirus Disease 2019) virus. Coronavirus Disease 2019 (COVID-19) is a novel virus. It causes severe acute respiratory syndrome. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the agent responsible for a surface-to-surface communicable disease that had infected approximately 4.7 million persons as of May 17, 2020.1Johns Hopkins UniversityCOVID-19 Dashboard by the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University (JHU).https://coronavirus.jhu.edu/map.htmlDate accessed: May 17, 2020Google Scholar Health care providers need options to limit and control the spread of the virus between themselves and patients. COVID-19 is an enveloped, positive-sense, single-stranded RNA virus approximately 60 to 140 nm in diameter. The virus's Spike glycoprotein S1 firmly binds to the angiotensin converting enzyme 2 (ACE2) receptor, which allows entry into the host cell.2Xu H. Zhong L. Deng J. et al.High expression of ACE2 receptor of 2019-nCoV on the epithelial cells of oral mucosa.Int J Oral Sci. 2020; 12: 8Crossref PubMed Scopus (1866) Google Scholar, 3Li H. Liu S.-M. Yu X.-H. et al.Coronavirus Disease 2019 (COVID-19): Current status and future perspectives.Int J Antimicrob Agents. 2020; 55: 105951Crossref PubMed Scopus (778) Google Scholar, 4Lu G. Wang Q. Gao G.F. Bat-to-human: Spike features determining 'host jump' of coronaviruses SARS-CoV, MERS-CoV, and beyond.Trends Microbiol. 2015; 23: 468Abstract Full Text Full Text PDF PubMed Scopus (426) Google Scholar COVID-19 infection creates a cytokine storm, severe pneumonia, multiple-organ failure, and acute cardiac injury.5Huang C. Wang Y. Li X. et al.Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China.Lancet. 2020; 395: 497Abstract Full Text Full Text PDF PubMed Scopus (33292) Google Scholar,6Zumla A. Hui D.S. Azhar E.I. et al.Reducing mortality from 2019-nCoV: Host-directed therapies should be an option.Lancet. 2020; 395: e35Abstract Full Text Full Text PDF PubMed Scopus (328) Google Scholar Transmission occurs through touch or aerosol spreading of the virus. A common pathway of spreading this virus is through respiratory aerosols from an infected person.7Lu H. Stratton C.W. Tang Y.W. Outbreak of pneumonia of unknown etiology in Wuhan China: The mystery and the miracle.J Med Virol. 2020; 92: 401Crossref PubMed Scopus (2136) Google Scholar During speech, humans emit thousands of oral fluid droplets per second that can remain airborne for 8 to 14 minutes.8Stadnytskyi C. Bax E. Bax A. Anfinrud P. The airborne lifetime of small speech droplets and their potential importance in SARS-CoV-2 transmission.Proc Nat Acad Sci. 2020; 117: 11875Crossref PubMed Scopus (767) Google Scholar COVID-19 is detectable for up to 3 hours in surface aerosols, for up to 4 hours on copper, for up to 24 hours on cardboard, and for up to 2 to 3 days on plastic and stainless steel.9Cottone J.A. Terezhalmy G.T. Molinari J.A. Practical Infection Control in Dentistry. Williams & Wilkins, Baltimore, MD1996: 139-140Google Scholar,10van Doremalen N. Morris D.H. Holbrook M.G. et al.Aerosol and surface stability of HCoV-19 (SARS-CoV-2) compared to SARS-CoV-1.N Engl J Med. 2020; 382: 1564Crossref PubMed Scopus (6789) Google Scholar There is a need to disinfect surfaces potentially exposed to COVID-19 to prevent transmission. On contact with the virus, a disinfectant agent changes the protective protein coat, which loses its structure and aggregates, forming clumps of proteins with other viruses.9Cottone J.A. Terezhalmy G.T. Molinari J.A. Practical Infection Control in Dentistry. Williams & Wilkins, Baltimore, MD1996: 139-140Google Scholar,10van Doremalen N. Morris D.H. Holbrook M.G. et al.Aerosol and surface stability of HCoV-19 (SARS-CoV-2) compared to SARS-CoV-1.N Engl J Med. 2020; 382: 1564Crossref PubMed Scopus (6789) Google Scholar Currently, the US Environmental Protection Agency has recommended numerous disinfectants against COVID-19 including hypochlorous acid (HOCl).11List N. US Environmental Protection AgencyDisinfectants for use against SARS-CoV-2.https://www.epa.gov/pesticide-registration/list-n-disinfectants-use-against-sars-cov-2Date accessed: May 17, 2020Google Scholar The mechanism of disinfection involves the destroying of the cell wall of microbes or viruses, allowing the disinfectant to destroy or inactivate them.12Suman R. Javaid M. Haleem A. et al.Sustainability of coronavirus on different surfaces [published online May 6, 2020].https://doi.org/10.1016/j.jceh.2020.04.020Google Scholar, 13Chen C. Zhang X.J. Wang Y. et al.Waste water disinfection during SARS epidemic for microbiological and toxicological control.Biomed Environ Sci. 2006; 19: 173PubMed Google Scholar, 14Hagbom M. Nordgren J. Nybom R. et al.Ionizing air affects influenza virus infectivity and prevents airborne-transmission.Sci Rep. 2015; 5: 11431Crossref PubMed Scopus (51) Google Scholar, 15McDonnell G. Russell A.D. Antiseptics and disinfectants: Activity, action, and resistance.Clin Microbiol Rev. 1999; 12: 147Crossref PubMed Google Scholar, 16Ding T. Xuan X.-T. Li J. et al.Disinfection efficacy and mechanism of slightly acidic electrolyzed water on Staphylococcus aureus in pure culture.Food Control. 2016; 60: 505Crossref Scopus (90) Google Scholar, 17Wolfe R.L. Ultraviolet disinfection of potable water—Current technology and research needs.Environ Sci Technol. 1990; 24: 768Crossref Scopus (148) Google Scholar, 18Xu P. Kujundzic E. Peccia J. et al.Impact of environmental factors on efficacy of upper-room air ultraviolet germicidal irradiation for inactivating airborne mycobacteria.Environ Sci Technol. 2005; 39: 9656Crossref PubMed Scopus (79) Google Scholar, 19Weber D.J. Kanamori H. Rutala W.A. 'No touch' technologies for environmental decontamination: Focus on ultraviolet devices and hydrogen peroxide systems.Curr Opin Infect Dis. 2016; 29: 424Crossref PubMed Scopus (81) Google Scholar, 20Health Quality OntarioPortable ultraviolet light surface-disinfecting devices for prevention of hospital-acquired infections: A health technology assessment.Ont Health Technol Assess Ser. 2018; 18: 1Google Scholar, 21Nerandzic M.M. Thota P. Sankar T. et al.Evaluation of a pulsed xenon ultraviolet disinfection system for reduction of healthcare-associated pathogens in hospital rooms.Infect Control Hosp Epidemiol. 2015; 36: 192Crossref PubMed Scopus (105) Google Scholar, 22Lidwell O.M. Ultraviolet radiation and the control of airborne contamination in the operating room.J Hosp Inf. 1994; 28: 245Abstract Full Text PDF PubMed Scopus (48) Google Scholar, 23Menetrez M.Y. Foarde K.K. Dean T.R. Betancourt D.A. The effectiveness of UV irradiation on vegetative bacteria and fungi surface contamination.Chem Eng J. 2010; 157: 443Crossref Scopus (36) Google Scholar, 24Moggio M. Goldner J.L. McCollum D.E. Beissinger S.F. Wound infections in patients undergoing total hip arthroplasty. Ultraviolet light for the control of airborne bacteria.Arch Surg. 1979; 14: 815Crossref Scopus (33) Google Scholar, 25Goldner J.L. Moggio M. Beissinger S.F. McCollum D.E. Ultraviolet light for the control of airborne bacteria in the operating room.Ann N Y Acad Sci. 1980; 353: 271Crossref PubMed Scopus (27) Google Scholar, 26Reed N.G. The history of ultraviolet germicidal irradiation for air disinfection.Public Health Rep. 2010; 125: 15Crossref PubMed Scopus (276) Google Scholar, 27Cadnum J.L. Li D.F. Redmond S.N. et al.Effectiveness of ultraviolet-C light and a high-level disinfection cabinet for decontamination of N95 respirators.Pathog Immun. 2020; 5: 52Crossref PubMed Scopus (76) Google Scholar This article focuses on HOCl. An ideal disinfectant and sanitizer must be nontoxic to surface contact, noncorrosive, effective in various forms, and relatively inexpensive. HOCl may be the disinfectant of choice for coronaviruses in an oral-maxillofacial surgery (OMS) office. HOCl is an endogenous substance in all mammals and is effective against a broad range of microorganisms. Neutrophils, eosinophils, mononuclear phagocytes, and B lymphocytes produce HOCl in response to injury and infection through the mitochondrial membrane–bound enzyme known as "respiratory burst nicotinamide adenine dinucleotide phosphate oxidase."28Kettle A.J. Winterbourn C.C. Myeloperoxidase A key regulator of neutrophil oxidant production.Redox Rep. 1997; 3: 3Crossref PubMed Scopus (609) Google Scholar HOCl selectively binds with the unsaturated lipid layer and subsequently disrupts cellular integrity. Between pH levels of 3 and 6, the predominant species is HOCl that has maximal antimicrobial properties.29Wang L. Bassiri M. Najafi R. et al.Hypochlorous acid as a potential wound care agent: Part I. Stabilized hypochlorous acid: A component of the inorganic armamentarium of innate immunity.J Burns Wounds. 2007; 6: e5PubMed Google Scholar,30Biology Stack ExchangeHow does hypochlorous acid inactivate viruses?.https://biology.stackexchange.com/questions/62671/how-does-hypochlorous-acid-inactivate-virusesGoogle Scholar HOCl is a powerful oxidizing agent. In aqueous solution, it dissociates into H+ and OCl–, denaturing and aggregating proteins.30Biology Stack ExchangeHow does hypochlorous acid inactivate viruses?.https://biology.stackexchange.com/questions/62671/how-does-hypochlorous-acid-inactivate-virusesGoogle Scholar HOCl also destroys viruses by chlorination by forming chloramines and nitrogen-centered radicals, resulting in single- as well as double-stranded DNA breaks, rendering the nucleic acid useless and the virus harmless.31Winter J. Ilbert M. Graf P.C.F. et al.Bleach activates a redox-regulated chaperone by oxidative protein unfolding.Cell. 2008; 135: 691Abstract Full Text Full Text PDF PubMed Scopus (302) Google Scholar HOCl can be made on-site combining non-iodinated salt, water, and electrolysis. The system to make HOCl on-site is a 1-L container that is filled with water, to which 1 g of non-iodized salt and 1 teaspoon of vinegar are added. The system has the ability to make concentrations of 50 to 200 ppm (in which 1 ppm is equal to 1 mg/L) depending on its use, which is chosen by pressing a button on the instrument. The electrolyzed solution is completed in 8 minutes, when it is ready for use. The parameters that contribute to HOCl's efficacy as a disinfectant include contact time and concentration.32Hawkins C.L. Davies M.J. Hypochlorite-induced damage to DNA, RNA, and polynucleotides: Formation of chloramines and nitrogen-centered radicals.Chem Res Toxicol. 2002; 15: 83Crossref PubMed Scopus (164) Google Scholar, 33Mourad K.A. Hobro S. Developing chlorine-based antiseptic by electrolysis.Sci Total Environ. 2020; 709: 136108Crossref PubMed Scopus (12) Google Scholar, 34Martin M.V. Gallagher M.A. An investigation of the efficacy of super-oxidised (Optident/Sterilox) water for the disinfection of dental unit water lines.Br Dent J. 2005; 198: 353Crossref PubMed Scopus (32) Google Scholar The method of application also will affect its efficacy to disinfect. Rossi-Fedele et al35Rossi-Fedele G. Dogramaci E.J. Steier L. de Figueiredo J.A. Some factors influencing the stability of Sterilox(®), a super-oxidised water.Br Dent J. 2011; 210: E23Crossref PubMed Scopus (15) Google Scholar investigated the shelf life of HOCl by being either exposed to or protected from sunlight. When the HOCl solution was exposed to sunlight, the chlorine reduction started on day 4. When it was sheltered from sunlight, the chlorine reduction started after day 14. The half-life increases with decreasing pH owing to the decreasing ratio of OCl–to HOCl.36Nowell L.H. Hoigné J. Photolysis of aqueous chlorine at sunlight and ultraviolet wavelengths—I. Degradation rates.Water Res. 1992; 26: 593Crossref Scopus (101) Google Scholar The parts per million (ppm) is the concentration of the –OCl, which is the active ingredient and is known as the available free chlorine (AFC) in the solution. HOCl solutions are less stable when exposed to UV radiation, sunlight, or contact with air or when the temperature of the solution is elevated greater than 25°C. HOCl solutions should be stored in cool, dark places, and contact with air should be minimized. The water for fabrication should be water that contains organic and inorganic ion concentrations that are as small as possible.37Rutala W.A. Cole E.C. Thomann C.A. Weber D.J. Stability and bactericidal activity of chlorine solutions.Infect Control Hosp Epidemiol. 1998; 19: 323Crossref PubMed Scopus (84) Google Scholar, 38Ishihara M. Murakami K. Fukuda K. et al.Stability of weakly acidic hypochlorous acid solution with microbicidal activity.Biocontrol Sci. 2017; 22: 223Crossref PubMed Scopus (53) Google Scholar, 39Kampf G. Todt D. Pfaender S. Steinmann E. Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents.J Hosp Inf. 2020; 104: 246Abstract Full Text Full Text PDF PubMed Scopus (2539) Google Scholar, 40Park G.W. Boston D.M. Kase J.A. et al.Evaluation of liquid- and fog-based application of Sterilox hypochlorous acid solution for surface inactivation of human norovirus.Appl Environ Microbiol. 2007; 73: 4463Crossref PubMed Scopus (95) Google Scholar HOCl has been shown to inactivate a variety of viruses including coronaviruses in less than 1 minute.39Kampf G. Todt D. Pfaender S. Steinmann E. Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents.J Hosp Inf. 2020; 104: 246Abstract Full Text Full Text PDF PubMed Scopus (2539) Google Scholar At a concentration of 200 ppm, HOCl is effective in decontaminating inert surfaces carrying noroviruses and other enteric viruses in a 1-minute contact time. When diluted 10-fold, HOCl solutions at 20 ppm were still effective in decontaminating environmental surfaces carrying viruses in a 10-minute contact time.40Park G.W. Boston D.M. Kase J.A. et al.Evaluation of liquid- and fog-based application of Sterilox hypochlorous acid solution for surface inactivation of human norovirus.Appl Environ Microbiol. 2007; 73: 4463Crossref PubMed Scopus (95) Google Scholar Individuals working in the dental and medical field using surgical and high-speed handpieces are at risk from aerosolization. Aerosols are defined as particles less than 50 μm in diameter. Particles of this size are small enough to stay airborne for an extended period before they settle on environmental surfaces or enter the respiratory tract.41Hinds W.C. Aerosol Technology: Properties, Behavior, and Measurement of Airborne Particles. Wiley, New York, NY1982Google Scholar,42Sotiriou M. Ferguson S.F. Davey M. et al.Measurement of particle concentrations in a dental office.Environ Monit Assess. 2008; 137: 351Crossref PubMed Scopus (55) Google Scholar Additionally, a true aerosol or droplet nuclei may be present in the air of the operatory for up to 30 minutes after a procedure.41Hinds W.C. Aerosol Technology: Properties, Behavior, and Measurement of Airborne Particles. Wiley, New York, NY1982Google Scholar Particles are classified based on size: Coarse particles measure 2.5 to 10 μm; fine particles, 0.1 μm to less than 2.5 μm; and ultrafine particles, less than 0.1 μm. The nose typically filters air particles larger than 10 μm. If a particle is smaller than 10 μm, it can enter the respiratory system. If smaller than 2.5 μm, it can enter the alveoli. A particle smaller than 0.1 μm, or an ultrafine particle, such as the COVID-19 virus, can enter the bloodstream or target the lungs. Sotiriou et al42Sotiriou M. Ferguson S.F. Davey M. et al.Measurement of particle concentrations in a dental office.Environ Monit Assess. 2008; 137: 351Crossref PubMed Scopus (55) Google Scholar showed that the concentrations of small particles (1 μm). Ultrasonic and sonic transmission during nonsurgical procedures had the highest incidence of particle transmission, followed by air polishing, air-water syringe, and high-speed handpiece aerosolization.43Veasey S. Muriana P.M. Evaluation of electrolytically-generated hypochlorous acid ('electrolyzed water') for sanitation of meat and meat-contact surfaces.Foods. 2016; 5: 42Crossref Scopus (44) Google Scholar One study found that ultrasonic instrumentation can transmit 100,000 microbes/ft3Li H. Liu S.-M. Yu X.-H. et al.Coronavirus Disease 2019 (COVID-19): Current status and future perspectives.Int J Antimicrob Agents. 2020; 55: 105951Crossref PubMed Scopus (778) Google Scholar with aerosolization of up to 6 ft and, if improper air current is present, microbes can last anywhere from 35 minutes to 17 hours.44Miller R.L. Characteristics of blood-containing aerosols generated by common powered dental instruments.Am Ind Hyg Assoc J. 1995; 56: 670Crossref PubMed Scopus (62) Google Scholar If HOCl is used as a mouth rinse, one must assume that a portion of the rinse will be swallowed. The systemic and gastrointestinal effects of ingesting HOCl, from the perspective of its use in mouthwash, was evaluated in an animal study.45Morita C. Nishida T. Ito K. Biological toxicity of acid electrolyzed functional water: Effect of oral administration on mouse digestive tract and changes in body weight.Arch Oral Biol. 2011; 56: 359Crossref PubMed Scopus (30) Google Scholar Seventeen mice were given free access to HOCl water as drinking water. No abnormal findings were observed in terms of visual inspections of the oral cavity, histopathologic tests, or measurements of surface enamel roughness, showing no systemic effect. HOCl is used in the treatment of blepharitis by reducing the bacterial load on the surface of the periocular skin. Twenty minutes after application of a saline hygiene solution containing HOCl at 100 ppm, a greater than 99% reduction in the staphylococcal load was achieved.46Stroman D.W. Keri Mintun K. Epstein A.B. et al.Reduction in bacterial load using hypochlorous acid hygiene solution on ocular skin.Clin Ophthalmol. 2017; 11: 707Crossref PubMed Scopus (51) Google Scholar HOCl may be effective for cleaning biofilm-contaminated implant surfaces. HOCl significantly lowered the lipopolysaccharide concentration of Porphyromonas gingivalis when compared with sodium hypochlorite and chlorhexidine and was well tolerated by the oral tissues.47Chen C.-J. Chen C.-C. Ding S.-J. Effectiveness of hypochlorous acid to reduce the biofilms on titanium alloy surfaces in vitro.Int J Mol Sci. 2016; 17: 1161Crossref Scopus (42) Google Scholar HOCl significantly reduced bacteria on toothbrushes; it was effective as a mouthwash and for toothbrush disinfection.48Lee S.H. Choi B.K. Antibacterial effect of electrolyzed water on oral bacteria.J Microbiol. 2006; 44: 417PubMed Google Scholar In a clinical study on intraperitoneal wound care, patients underwent lavage of the peritoneal cavity with 100-ppm HOCl and washing of the wound with 200 ppm.49Kubota A. Goda T. Tsuru T. et al.Efficacy and safety of strong acid electrolyzed water for peritoneal lavage to prevent surgical site infection in patients with perforated appendicitis.Surg Today. 2015; 45: 876Crossref PubMed Scopus (27) Google Scholar No adverse effects were observed. HOCl has been shown to be an effective agent in reducing wound bacterial counts in open wounds.50Hiebert J.M. Robson M.C. The immediate and delayed post-debridement effects on tissue bacterial wound counts of hypochlorous acid versus saline irrigation in chronic wounds.Eplasty. 2016; 16: e32PubMed Google Scholar In irrigation solution in an ultrasonic system, HOCl lowered the bacterial counts by 4 to 6 logs. By the time of definitive closure, the bacterial counts were back up to 105 for the saline solution–irrigated control wounds but remained at 102 or lower for the HOCl-irrigated wounds. Postoperative closure failure occurred in more than 80% of patients in the saline solution group versus 25% of those in the HOCl group. Hand antiseptics are alcohol based or non–alcohol based containing antibiotic compounds.51US Department of Health and Human Services–Food and Drug Administration Center for Drug Evaluation and ResearchConsumer antiseptic wash final rule questions and answers: Guidance for industry.https://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/UCM568513.pdfGoogle Scholar Chlorine-based sanitizers, at a concentration of 50 to 100 ppm, are effective against bacteria and viruses.52Wolfe M.K. Gallandat K. Daniels K. et al.Handwashing and Ebola virus disease outbreaks: A randomized comparison of soap, hand sanitizer, and 0.05% chlorine solutions on the inactivation and removal of model organisms Phi6 and E. coli from hands and persistence in rinse water.PLoS One. 2017; 12e0172734Crossref PubMed Scopus (40) Google Scholar HOCl specifically used for hand sanitizers is effective at 100- to 200-ppm strengths.53Medical Press: Hypochlorous acid water generator highly effective in removing bacteria and deodorizing.https://medicalxpress.com/news/2016-03-hypochlorous-acid-highly-effective-bacteria.htmlGoogle Scholar,54D&D Electronics: About disinfection generator NaOClean.http://dndele.tradekorea.com/company.doGoogle Scholar A study looked at disinfecting outpatient surgical centers using HOCl.55Overholt B. Reynolds K. Wheeler D. 1151. A safer, more effective method for cleaning and disinfecting GI endoscopic procedure rooms.Open Forum Infect Dis. 2018; 5: S346Crossref Google Scholar After cleaning, the rooms in the HOCl cleaning and disinfection study arm had significantly lower bacterial counts than the rooms that underwent standard cleaning and disinfection. A fogger takes a solution and creates a small aerosol mist, ideally less than 20 μm in size, to disinfect an area. HOCl fogs are highly effective in the microbial disinfection of surfaces. The fogging process can alter the physical and chemical properties of the disinfectant. It was found that fogging reduced the AFC concentration by approximately 70% and increased the pH by approximately 1.3, making the solution slightly more basic; it is speculated that the loss of chlorine resulted from evaporation of chlorine gas.56McRay R.J. Dineen P. Kitzke E.D. Disinfectant fogging techniques.Soap Chem Spec. 1964; 40: 112Google Scholar,57Zhao Y. Xin H. Zhao D. et al.Free chlorine loss during spraying of membraneless acidic electrolyzed water and its antimicrobial effect on airborne bacteria from poultry house.Ann Agric Environ Med. 2014; 21: 249Crossref PubMed Scopus (32) Google Scholar Because the changes in the properties of hypochlorous fogs are predictable, pre-fogging adjustment of the concentration and pH of the solution makes it possible to control the concentration levels to the desirable range to inactivate pathogens after fogging.40Park G.W. Boston D.M. Kase J.A. et al.Evaluation of liquid- and fog-based application of Sterilox hypochlorous acid solution for surface inactivation of human norovirus.Appl Environ Microbiol. 2007; 73: 4463Crossref PubMed Scopus (95) Google Scholar When the appropriate concentrations are used, a study found 3 to 5 log10 reductions in both the infectivity and RNA titers of all tested viruses on both vertical and horizontal surfaces, suggesting that fogging is an effective approach to reduce viruses on surfaces.40Park G.W. Boston D.M. Kase J.A. et al.Evaluation of liquid- and fog-based application of Sterilox hypochlorous acid solution for surface inactivation of human norovirus.Appl Environ Microbiol. 2007; 73: 4463Crossref PubMed Scopus (95) Google Scholar,58Galvin S. Boyle M. Russell R.J. et al.Evaluation of vaporized hydrogen peroxide, Citrox and pH neutral Ecasol for decontamination of an enclosed area: A pilot study.J Hosp Inf. 2012; 80: 67Abstract Full Text Full Text PDF PubMed Scopus (24) Google Scholar HOCl solutions appear to be virucidal based on concentrations above 50 ppm. HOCl was evaluated against a low-pathogenic avian influenza virus (AIV), H7N1.59Hakimullah H. Thammakarn C. Suguro A. et al.Evaluation of sprayed hypochlorous acid solutions for their virucidal activity against avian influenza virus through in vitro experiments.J Vet Med Sci. 2015; 77: 211Crossref PubMed Scopus (40) Google Scholar The HOCl solutions contained 50-, 100-, and 200-ppm chlorine at pH 6. Spraying with HOCl decreased the AIV titer to an undetectable level (<2.5 log10TCID50/mL) within 5 seconds, with the exception of the 50-ppm solution harvested after spraying at a distance of 30 cm. When HOCl solutions were sprayed directly onto sheets containing the virus for 10 seconds, the solutions of 100 and 200 ppm inactivated AIV immediately. The 50-ppm solution required at least 3 minutes of contact time. These data suggest that HOCl can be used in spray form to inactivate AIV.59Hakimullah H. Thammakarn C. Suguro A. et al.Evaluation of sprayed hypochlorous acid solutions for their virucidal activity against avian influenza virus through in vitro experiments.J Vet Med Sci. 2015; 77: 211Crossref PubMed Scopus (40) Google Scholar,60Tamaki S. Bui V.N. Ngo L.H. et al.Virucidal effect of acidic electrolyzed water and neutral electrolyzed water on avian influenza viruses.Arch Virol. 2014; 149: 405Crossref Scopus (34) Google Scholar When the aerosol was not sprayed directly onto an inoculated surface, a lower amount of solution had a chance to come into contact with the AIV. It required at least 10 minutes of contact to be effective.61Hao X.X. Li B.M. Zhang Q. et al.Disinfection effectiveness of slightly acidic electrolysed water in swine barns.J Appl Microbiol. 2013; 115: 703Crossref PubMed Scopus (47) Google Scholar The ability of a sprayer to make smaller particles may help a solution's molecules to be suspended in the air for a longer period because of their low settling velocity rate. This may increase the solution's chance of coming into contact with pathogens and inactivating them. Thus, the fogger used should have an aerosol size less than 20 μm.62Hinds W.C. Aerosol technology.in: Properties, Behavior, and Measurement of Airborne Particles. ed 2. John Wiley & Sons, New York, NY1999: 25-45Google Scholar The coronavirus pandemic has caused both a massive health care and economic disruption across the world. The current unavailability of an effective antiviral drug or approved vaccine means that the implementation of effective preventive measures is necessary to counteract COVID-19. Oral-maxillofacial surgeons are high-risk providers providing needed care to patients. As more OMS and surgical offices open during reopening in the United States and elsewhere in the world, the need to reduce the risk of transmission of COVID-19 between patients and providers is necessary. It is widely believed that with proper screening and discretion, along with adequate personal protective equipment, there is a low probability of becoming infected. The goal of this article is to provide information regarding disinfection in the clinical office setting using HOCl, a relatively inexpensive, nontoxic, noncorrosive, and well-studied compound. HOCl has uses in many industries from farming and restaurants, regarding food, to health care applications, including chronic wound care and disinfection.34Martin M.V. Gallagher M.A. An investigation of the efficacy of super-oxidised (Optident/Sterilox) water for the disinfection of dental unit water lines.Br Dent J. 2005; 198: 353Crossref PubMed Scopus (32) Google Scholar,36Nowell L.H. Hoigné J. Photolysis of aqueous chlorine at sunlight and ultraviolet wavelengths—I. Degradation rates.Water Res. 1992; 26: 593Crossref Scopus (101) Google Scholar,43Veasey S. Muriana P.M. Evaluation of electrolytically-generated hypochlorous acid ('electrolyzed water') for sanitation of meat and meat-contact surfaces.Foods. 2016; 5: 42Crossref Scopus (44) Google Scholar,45Morita C. Nishida T. Ito K. Biological toxicity of acid electrolyzed functional water: Effect of oral administration on mouse digestive tract and changes in body weight.Arch Oral Biol. 2011; 56: 359Crossref PubMed Scopus (30) Google Scholar,46Stroman D.W. Keri Mintun K. Epstein A.B. et al.Reduction in bacterial load using hypochlorous acid hygiene solution on ocular skin.Clin Ophthalmol. 2017; 11: 707Crossref PubMed Scopus (51) Google Scholar,63Su Y.-C. Liu C. Hung Y.-C. Electrolyzed water: Principles and applications.in: Zhu P. New Biocides Development, the Combined Approach of Chemistry and Microbiology. American Chemical Society, Washington, DC2007: 309-321Crossref Google Scholar In addition to the use of HOCl as a liquid-based disinfectant, fogging with hypochlorous vapor has shown virucidal activity against numerous types of viruses and bacteria.40Park G.W. Boston D.M. Kase J.A. et al.Evaluation of liquid- and fog-based application of Sterilox hypochlorous acid solution for surface inactivation of human norovirus.Appl Environ Microbiol. 2007; 73: 4463Crossref PubMed Scopus (95) Google Scholar,56McRay R.J. Dineen P. Kitzke E.D. Disinfectant fogging techniques.Soap Chem Spec. 1964; 40: 112Google Scholar,57Zhao Y. Xin H. Zhao D. et al.Free chlorine loss during spraying of membraneless acidic electrolyzed water and its antimicrobial effect on airborne bacteria from poultry house.Ann Agric Environ Med. 2014; 21: 249Crossref PubMed Scopus (32) Google Scholar This is of potential benefit to disinfect large spaces such as medical and dental offices where aerosols can be airborne for extended periods.42Sotiriou M. Ferguson S.F. Davey M. et al.Measurement of particle concentrations in a dental office.Environ Monit Assess. 2008; 137: 351Crossref PubMed Scopus (55) Google Scholar,44Miller R.L. Characteristics of blood-containing aerosols generated by common powered dental instruments.Am Ind Hyg Assoc J. 1995; 56: 670Crossref PubMed Scopus (62) Google Scholar,64Harrel S.K. Molinari J. Aerosol and splatter in dentistry: A brief review of the literature and infection control implications.J Am Dent Assoc. 2004; 135: 429Abstract Full Text Full Text PDF PubMed Scopus (556) Google Scholar In terms of particle size, oral-maxillofacial surgeons may be at a slightly lower risk than their dental counterparts because ultrasonic scaling and high-speed handpieces create smaller particles that remain airborne longer.42Sotiriou M. Ferguson S.F. Davey M. et al.Measurement of particle concentrations in a dental office.Environ Monit Assess. 2008; 137: 351Crossref PubMed Scopus (55) Google Scholar However, aerosols are still created with surgical handpieces. Additionally, the COVID-19 virus can be present on some surfaces for days, and the disinfection of all surfaces of an operatory is important to reduce transmission.9Cottone J.A. Terezhalmy G.T. Molinari J.A. Practical Infection Control in Dentistry. Williams & Wilkins, Baltimore, MD1996: 139-140Google Scholar,10van Doremalen N. Morris D.H. Holbrook M.G. et al.Aerosol and surface stability of HCoV-19 (SARS-CoV-2) compared to SARS-CoV-1.N Engl J Med. 2020; 382: 1564Crossref PubMed Scopus (6789) Google Scholar Many properties of HOCl contribute to why it may be the disinfectant of choice in the OMS setting. Although the shelf life of HOCl is relatively short, it is effective for up to 2 weeks under ideal conditions.35Rossi-Fedele G. Dogramaci E.J. Steier L. de Figueiredo J.A. Some factors influencing the stability of Sterilox(®), a super-oxidised water.Br Dent J. 2011; 210: E23Crossref PubMed Scopus (15) Google Scholar It can be made on-site inexpensively. A gallon of HOCl can be purchased from manufacturers but it is far more economical for an oral-maxillofacial surgeon to produce the solution on-site in the office.65Curio Dental: All purpose cleaner w/hypochlorous acid gallon.https://curio.dental/products/all-purpose-cleaner-w-hypochlorous-acid gallon?variant=32482507260003&currency=USDGoogle Scholar A variety of HOCl systems costing less than $275 are available on the market.66EcoloxTech: Generate hypochlorous acid (HOCl).https://www.ecoloxtech.comGoogle Scholar By combining non-iodinated salt, water, and electricity,33Mourad K.A. Hobro S. Developing chlorine-based antiseptic by electrolysis.Sci Total Environ. 2020; 709: 136108Crossref PubMed Scopus (12) Google Scholar 1 L of HOCl can be made in 8 minutes and the process can be repeated many times throughout the day. By comparison, a pack of common disinfecting wipes containing quaternary ammonium compounds costs between $4 and $15 for a pack containing 80 sheets. These wipes may only last a day or two depending the size of the office and area to clean. Shortages of these products can occur, making sourcing them difficult as well.67Diaz D. Zaslav A. Don't expect to see disinfectant wipes or sprays in stores anytime soon, experts say.https://www.cnn.com/2020/04/29/politics/lysol-wipes-back-in-stores-when-disinfectant-sprays/index.htmlGoogle Scholar In addition to using HOCl in the form of wipes for disinfecting, using HOCl vapors through a fogging machine is an economical way to disinfect a large operating room or suite in which aerosols were produced during surgery. Foggers or misting machines are handheld machines and can be purchased for a reasonable cost.68The Home DepotRyobi One+ 18-volt lithium-ion cordless fogger/mister with 2.0 Ah battery and charger included.https://www.homedepot.com/p/RYOBI-ONE-18-Volt-Lithium-Ion-Cordless-Fogger-Mister-with-2-0-Ah-Battery-and-Charger-Included-P2850/307244559Google Scholar The aerosol mist ideally should be less than 20 μm in size to maximally disinfect an area. It is important to note that the fogging process can alter the physical and chemical properties of the disinfectant, making it more dilute and basic. As mentioned before, the AFC concentration can be reduced by approximately 70% and the pH can increase by about 1.3.40Park G.W. Boston D.M. Kase J.A. et al.Evaluation of liquid- and fog-based application of Sterilox hypochlorous acid solution for surface inactivation of human norovirus.Appl Environ Microbiol. 2007; 73: 4463Crossref PubMed Scopus (95) Google Scholar To make a vapor as effective as a solution containing 100 ppm of HOCl, the solution would need to be concentrated. The fine mist can be left in the empty surgical room without thought regarding harmful chemical effects; the surfaces are then wiped clean and dry after a few minutes and, for a more dilute solution, after 10 minutes. HOCl is one disinfectant that, when combined with adequate personal protective equipment, screening and social-distancing techniques, hand washing, and high-volume evacuation suction, may help reduce the transmission of COVID-19 in the outpatient OMS setting. It comprises many of the desired effects of the ideal disinfectant: It is easy to use, is inexpensive, has a good safety profile, and can be used to disinfect large areas quickly and with a broad range of bactericidal and virucidal effects.