Next Article in Journal
Identifying the Biogeographic Patterns of Rare and Abundant Bacterial Communities Using Different Primer Sets on the Loess Plateau
Next Article in Special Issue
Virucidal Effect of the Mesoscopic Structure of CAC-717 on Severe Acute Respiratory Syndrome Coronavirus-2
Previous Article in Journal
One Pathway, Two Cyclic Non-Ribosomal Pentapeptides: Heterologous Expression of BE-18257 Antibiotics and Pentaminomycins from Streptomyces cacaoi CA-170360
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Microorganisms
Volume 9
Issue 1
10.3390/microorganisms9010136
microorganisms-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Review

New Clinical Applications of Electrolyzed Water: A Review

by
Pianpian Yan
,
Eric Banan-Mwine Daliri
and
Deog-Hwan Oh
*
Department of Food Science and Biotechnology, Kangwon National University, Chuncheon 24341, Korea
*
Author to whom correspondence should be addressed.
Microorganisms 2021, 9(1), 136; https://doi.org/10.3390/microorganisms9010136
Submission received: 1 December 2020 / Revised: 5 January 2021 / Accepted: 5 January 2021 / Published: 8 January 2021
(This article belongs to the Special Issue Disinfection, Sterilization and Decontamination of Microorganisms)
Browse Figures
Versions Notes

Abstract

:
As the situation of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is still deteriorating, there has been a huge increase in the demand and use of disinfectants. Electrolyzed water (EW), as a novel broad-spectrum disinfectant and cleaner, has been widely used for several years. EW can be produced in an electrolysis chamber which contains dilute salt and tap water. It is an effective antimicrobial and antibiofilm agent, with several advantages such as on-the-spot, cheap, environmentally friendly and safe for human beings. Therefore, EW holds potential significance for high-risk settings in hospitals and other clinical facilities. EW can also be applied for wound healing, advanced tissue care, and dental clinics. The present review article highlights the latest developments and new perspectives of EW, especially in clinical fields. Furthermore, the main action modes of antibiofilm and antimicrobial will be summarized.

1. Introduction

The Center for Disease Control and Prevention (CDC) has recently reported that there is at least one person who has a healthcare-associated infection in every 31 hospital patients in any given day [1]. Such healthcare-associated infections (HAI) include central line-associated bloodstream infection, catheter-associated urinary tract infections, surgical site infection and ventilator-associated pneumonia [2]. HAIs are a major cause of morbidity and even mortality in the United States [3]. The healthcare environment is a primary source of pathogenic microorganisms [4]. Molds may be present on wet or damp surfaces or materials [5]. Bacteria may also be present in bathroom installations, including sink drains and ice machines. Furthermore, surgical site infections can sometimes be superficial infections involving the skin [6,7]. At the same time, infections in other surgical sites could be more serious, which may involve tissues under the skin, organs, or even implanted materials [8,9]. Infections also increase the length of stay, readmission rates, costs, and even mortality [10,11]. Biofilms are responsible for causing 80% of human infections. The National Institutes of Health (NIH) reported that biofilms are responsible for up to 80% of human bacterial infection [12].
Therefore, developing effective disinfectants and antiseptics for killing pathogens and destroying the biofilm formation in the environment and human healthcare is one of the most significant steps for infection prevention and control. The medical industry has employed a number of decontamination techniques throughout the hospital and healthcare clinical field [13,14,15]. However, some of these techniques have disadvantages such as high cost, low efficacy, remaining chemical residues, and adverse effects irritation on the human skin [16,17]. As an important premise for practical application, it should have high antimicrobial efficacy and no toxicity to the human body [18].
Electrolyzed water (EW) is a novel disinfectant and cleaner which has been widely used in the food industry for several years to ensure the sterilization of surfaces and safety of food [19,20,21,22]. EW is produced in an electrolysis chamber which contains dilute salt and tap water without any harmful chemical addition [23]. EW has antimicrobial effects against a variety of microorganisms including common biofilm, viruses, bacteria, spores and fungi in chronic wounds and environmental surfaces [24,25,26,27,28,29]. Currently, due to its beneficial properties (anti-infection and cell proliferative), researchers pay more attention to the application of electrolyzed water in clinical treatments including medical sterilization. The US Environmental Protection Agency (EPA) recommended the use of disinfectants with hypochlorite acid as active ingredients for the disinfection of surfaces against COVID-19 [30]. Furthermore, various studies have been carried out on the antimicrobial activity of EW against different illments, including diabetic foot ulcers [31,32], venous ulcers in the legs [33,34] or feminine hygiene [35,36].
However, some studies have reported that the application of EW is limited by factors such as the corrosion of equipment which is in contact with acidic or basic EW and the ability of organics materials (proteins, lipids and so on) to shorten its shelf life [37,38]. To overcome these defects, hurdle technology, which is a combination of two or more low-dose disinfection and preservatives techniques could be applied [39]. Therefore, EW combined with other disinfection methods could be an effective way to obtain a desirable result [40,41].
The aim of this review was to introduce recent developments and provide a new perspective with EW in the clinical field. Many characteristics of electrolyzed water in this review article were introduced including the physiochemical properties, history, limitation principle, generation methodologies, and the impact of these characteristics on the sanitizing efficacy of EW. In addition, applications of EW for microbial control in the clinical field are also discussed.

2. Principles and History of EW

The development history of electrolyzed water can be traced back for more than a century [42]. The concept of electrolyzed water was first proposed in Russia [43]. However, it has been widely used for various purposes including disinfection, water regeneration and water decontamination in Japan since 1980. As time went by, its application has extended to other fields such as the food industry, agriculture, livestock management and clinical application [44,45,46,47]. Figure 1 illustrates the application of EW in different areas at different pH values.
Electrolyzed reduced water was invented in the early 19th century [48]. Research on electrolyzed water started in Japan around 1931 and its application and popularity to agriculture in the 1950s. In 1960, the water was applied to medical care and in 1966, electrolyzed reduced water was touted as having “healing effects” including indigestion, chronic diarrhea, antacid, abnormal gastrointestinal fermentation, and hyperacidity [49]. A device for the preparation of ERW was authorized for home-use by the Ministry of Health, Labor, and Welfare of Japan [50].
In 1994, with the support of the Ministry of Health, Labor, and Welfare of Japan, the functional water foundation was established to promote the use of electrolyzed water in society. Based on considerable scientific evidence related to the risk assessment of EW, in 2005, the Drugs, Cosmetics and Medical Instruments Act of Japan was revised and re-authorized an ERW-producing device as a home-managed medical device. In 2002, the Ministry authorized the use of hypochlorous acid water on designated food additives. Recently, in 2017, the US Food and Drug Administration (USFDA) also authorized hypochlorous acid (electrolytically generated on-site) for use on food contact surfaces (FCS) [51]. In addition, Chinese standardization administration published a series of criteria in 2020, related to hypochlorous acid water, which can be used for human skin, hand and mucous membrane. Table 1 illustrates the criteria of application of EW in different countries.

3. Systems for Generation of Electrolyzed Water

Electrolyzed water (EW) is produced in an electrolysis chamber which contains hydrogen chloride (HCl) solution or dilute salt (NaCl) [52]. According to the different devices, electrolyte and electrolysis conditions, EW can be classified into the following categories: acidic electrolyzed water, neutral electrolyzed water and alkali electrolyzed water [53]. The characteristic of EW is shown in Table 2. The application of EW can be roughly divided into alkali water for drinking and electrolytic water for cleaning, sterilization, and disinfection [49,54,55,56].
These solutions are produced by the electrolysis of dilute salt (NaCl) passing through two or three cell electrolyzers with the anode and cathode separated by a diaphragm. It can produce two types of water simultaneously. Acidic electrolyzed water (AEW), with a pH of 2 to 3, available chlorine concentration (ACC) of 10 to 90, and oxidation–reduction potential (ORP) >1100 Mv, is produced at the anode side [23]. At the same time, basic electrolyzed water (BEW) with a pH of 10 to 13, and ORP from −800 to −900 Mv is generated at the cathode side. Nowadays, there are some novel forms of electrolyzed water such as slightly acid electrolyzed water (SAEW), weak acid electrolyzed water (WAEW) and neutral electrolyzed water (NEW) [57,58,59]. SAEW is very popular in Japan, China and Korea [60,61,62]. SAEW (pH of 5.5–6.5, ACC of 10–80 ppm and ORP of 800–900 Mv), and NEW (pH of 7–8 and ORP of 750–900 Mv) are produced by using single-cell chambers. SAEW is produced by the electrolysis of HCl alone or combined with NaCl in a single-cell unit (without diaphragm) [63]. It is expected that the SAEW will not lose its superior features after mixing due to the unipolar reaction in the process of electrolysis. In addition to the above method, NEW can also be produced by a mixture of the anodic solution with OH− ions [64]. The details are shown in Figure 2. EW can also be stored in containers of special materials or converted into ice cubes for future use [65].

4. Factors Influencing Decontamination Efficacy of Electrolyzed Water

4.1. Direct Factors

The concentration of chlorine (Cl2, OCl−, and HOCl), ORP, and pH directly play an important role in the antimicrobial efficacy of EW (shown in the Figure 3). HOCl is the most effective inactivation compound in the chlorine group [66]. They found that the inactivation efficacy of HOCl was 80-fold higher than that of an equivalent concentration of OCl− when the pH value of the solution was from 5.0 to 6.5. Ding et al. reported that SAEW treatment on S. aureus for 1 min reduced 5.8 log CFU/mL, but sodium hypochlorite (NaClO) decreased by the bacteria by 3.26 log CFU/mL [67]. This might be explained by considering that the electrical properties of the HOCl and OCl− are different. HOCl is neutral, whereas the hypochlorite ion (OCl−) and bacterial membrane are both negative [68]. Therefore, HOCl can more easily penetrate target cells to exert strong bactericidal effects based on Coulomb’s law. However, the fraction of chlorine species depends on the pH of the solution [69]. HOCl is a weak acid with a pKa of about 7.46 [70]. Therefore, if the pH value is low (pH < 4), it is possible to form Cl2. When the pH value is above 7.5, HOCl is decomposed into hydrogen ion (H+) and hypochlorite ion (OCl−) in the reversible reaction [70]. HOCl, as one of the reactive oxygen species (ROS), infiltrates the membranes of bacteria cells and kills pathogens through chlorination or oxidation, which destructs the key metabolic frameworks [71]. In addition, there are a few reports of the inactivation action being mainly affected by the ORP of EW. They reported that high ORP may result in modifying the metabolic flux and ATP production [72]. Liao et al. studied the inactivation mechanism of ORP in EOW. The results showed that EOW with higher ORP had a higher efficiency of the inactivation of E. coli O157:H7 by damaging the outer membrane and inner membrane, thus releasing the intracellular component [73].

4.2. Indirect Factors

The concentration of electrolyte, water flow rate and water source (hardness) indirectly influence the effectiveness of EW(shown in the Figure 3). However, the above factors are linearly correlated to the amount of HOCl and ORP in the process of electrolysis and ultimately reduce or increase the decontamination efficacy of EW (the properties of EW).
Kim et al. [26] examined the effects of the water hardness of SAEW in inactivating Staphylococcus aureus, Salmonella enterica serovar Typhimurium, Escherichia coli, and Bacillus cereus spores. The results showed that the ACC of SAEW produced by tap water (hardness = 29 ppm) is better than that of underground water (hardness = 12 ppm). The hardness of water is mainly dependent on the content of calcium and magnesium [74]. There is a positive correlation between salinity and conductivity. In addition, electrical conductivity and the total chlorine concentration of the electrolyzed oxidizing water increased with the increasing salt concentration. When the concentration of salt (KCl) was increased from 2.0 M to 3.0 M, the ACC increased from 56.5 to 65.5 ppm in the same time [26].
Moreover, the water flow rate affects the ACC. Hsu et al. reported that the total ACC and ORP of electrolyzed oxidizing water was significantly decreased when water flow rate and salt concentration increased in the feed solution [75]. The reasons are maybe that the higher flow rate leads to less residence of ions in the electrolysis cell per unit time, chloride ions and sodium ions could not be sufficiently electrolyzed and moved to the anode side [74]. Therefore, more sodium, chloride ions and less HOCl remained in the feed water.

5. The Advantages and Disadvantages of Electrolyzed Water

There are many advantages of EW over its toxic counterparts (physical, chemical and biological technology) in different areas such as agriculture, food hygiene, medical field and even in human surface disinfection. The advantages of electrolyzed water can be easily enumerated.
First, EW has been proposed as an environmentally friendly alternative to physical and chemical methods, which do not contain undesirable toxic contaminants [76]. As previously mentioned above, EW is only produced from NaCl and tap water and reverts to regular water after use [77]. Second, EW has a broad-spectrum inactivation ability and rapid antibacterial activity, which possesses nonselective properties [78,79]. HOCl was produced by an enzyme called myeloperoxidase, which uses hydrogen peroxide (H2O2) in our body as a substrate to react with neutrophils. [80]. HOCl is a naturally occurring molecule and has strong bactericidal ability to serve as a reliable defense system [78]. Medina et al. reported that artificially contaminated eggs with Salmonella or E. coli reduced >1.45 Log10 CFU/egg and >6.39 Log10 CFU/egg, respectively, after 30 s treatment of NEW [72]. Third, EW-producing machines have the ability for on-site generation at the location of intended use inexpensively [23]. The volume of 1 L of EW can be made in 8 min and the process can be repeated multiple times a day [19]. Therefore, it can prevent chlorination problems during handling, storage, and transport. Additionally, the use of AEW, alkaline electrolyzed water (AlEW), NEW, and SAEW do not cause negative organoleptic changes in food [49,81,82]. Finally, NEW and SAEW have a neutral pH and are safe, with no irritation on mucous membrane and skin [83].
When tackling the disadvantages and advantages of EW, we also need to point out the adverse impact of this novel technology. First, EW is a sanitizer produced from tap water with sodium chloride (NaCl) without the addition of harmful chemicals [84]. However, it still contains chemical compounds. The USFDA published a regulation that when EW is used to process fruits, vegetables, ready-to-eat meats, fish and seafood products intended to be consumed raw, the treatment will be followed by either a 10 min drain step or a potable water rinse to remove residues [51]. In addition, the Ministry of Health, Labour and Welfare (Japan) issued an act to remove HOCl before it becomes the final product. Second, the concentration of chlorine decreases over time, and loses its antimicrobial potential quickly [85]. Third, the degradation of synthetic resins and metal corrosion can be caused by high ORP or the free chlorine content during the use of AEW [22,86].

6. Disinfection Mechanisms of EW

In order to produce the safe and effective use of disinfectants, numerous disinfection methods have been studied and reported over the years. Many researchers have fully studied the mechanism of traditional disinfection methods such as physical treatments (heat and irradiation etc.) and chemical disinfectants (hydrogen peroxide and chlorine dioxide etc.) [87]. However, the exact mechanisms underlying microbial inactivation by EW have not been fully elucidated. It is well known that chlorine (Cl2, −OCl, and HOCl) plays an important role in the antimicrobial efficacy of electrolyzed water [88]. HOCl can penetrate the lipid bilayer of the cell membrane by passive diffusion due to its molecular size (which is equivalent to water (H2O)) and its electrical neutrality [89]. In addition, HOCl is a powerful oxidizing agent, which denatures and aggregates proteins [90]. These may be the reason for the excellent germicidal activity of HOCl. Ding et al. found that SAEW disrupted cell membrane permeability by damaging membrane proteins, entering the cells and causing the agglutination of cellular inclusions in S. aureus [67]. Furthermore, Tang et al. reported that EOW decreased the activity of TCC-dehydrogenase, intensified the permeability of the membrane, increased the conductivity of suspension, and resulted in the leakage of K+, protein and DNA, which indicated that the cell wall and membrane were damaged [91]. However, OCl– cannot penetrate the microbial cell and microbial membrane because there is a lipid bilayer in the plasma membrane (hydrophobic layer) [92]. OCl− only exhibits an oxidizing action from outside the cell, which would inactivate functional proteins localized in the plasma membrane [93]. In addition to the chlorine family, other compounds (reactive oxygen species) can be produced in the process of electrolysis, which contributes to the antimicrobial efficiency [94]. Figure 4 shows the mechanism of HOCl and OCl– reaction on pathogens. The exact pattern of EW on microbial cells is still unclear and requires more investigations to clarify in the future.

7. Use of EW for Clinical Application

Recently, the Ministry of Health of the People’s Republic of China released three Chinese standards for materials and restricted substances in disinfectants, general requirements for hand disinfectants and general requirements for the disinfectants of mucous membrane in April 2020 [95,96]. In short, EW can not only be used for disinfecting medical instruments, clinical environments and object surfaces, but also disinfecting hands, skin, and mucous membranes. In addition, the US Environmental Protection Agency has recommended many disinfectants for COVID-19, including HOCl. Currently, there are a variety of EW-based disinfection products on the market. The approved core formula is HOCl, which can remain stable for up to twelve months without cytotoxicity [97]. Importantly, its pH neutralization can enhance therapeutic activity, stability and skin tolerability. Many patents including the use of EW application for advanced tissue care, dermatology and dental care are available [98,99,100]. The application of EW in the clinical field was shown in Table 3.

7.1. Wound Care

A topical antibacterial agent, which can reduce the bacterial biological load of the wound without impairing the healing ability, is an imperative condition for therapy [124]. Wound healing is a complex process including multiple stages: hemostasis, inflammation, proliferation and tissue remodeling [125]. The timely resolution of each healing process is critical for promoting healing and avoiding excess scar formation. Currently, the treatments for impaired wound healing focus mainly on the optimization of controllable factors including the clearance of infections, mechanical protection, and nutritional support [126]. Wound care should also minimize scarring and inflammation. Recently, EW with antimicrobial properties has been utilized as part of cell proliferation, anti-infection and anti-biofilm therapies in a wound healing agent (shown in the Figure 5) [114,127]. Ben et al. found that with the application of MicroSafe® as an instillation fluid with a novel foam dressing and negative pressure wound therapy for the patient, the wound bed showed dramatic improvement after three days of treatment [128]. Sasai et al. also studied the potential use of AEW for patients with atopic dermatitis. Their results also revealed that the treatment with 3 min spraying and after 1 week of skin reduced the Staphylococcus aureus count by about 3.80 log/cm2 reduction without any detrimental effect [108]. Scientists reported that electrolyzed water has an effect on skin wound healing. Tiroda et al. reported that nine patients (23%) using superoxidized solution improved by at least 75% in the reduction in lesions [129]. Additionally, biofilm formation causes prolonged wound infections due to the dense biofilm structure, differential gene regulation to combat stress, and the production of extracellular polymeric substances [112]. HOCl (active compound) is able to increase oxygenation (TcPO2) in wounds while breaking biofilms, which is an important key differentiator from other products [130].

7.2. Hand Sanitizer

Hand sanitization is the most important but simple way to remove germs, prevent the spread of germs to others and avoiding illness [131]. For EW-based hand sanitizers sold in China, the concentration of ACC usually ranges from 30 to 150 ppm, which is effective against viruses and bacteria. In addition to using EW as a liquid-based disinfectant, EW in fog form also show an antibacterial effect against numerous types of bacteria [123]. Pathogens related to hand hygiene and healthcare include Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus hirae, Candida albicans. Sipahi et al. reported the inactivation effect of StAEW, SAEW, mixed electrolyzed water (MEW) and catholyte (CEW) on Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus hirae, Candida albicans. They found that StAEW, SAEW, and MEW reduced the agents significantly. StAEW was especially effective against test microorganism (Pseudomonas aeruginosa, Enterococcus hirae and Candida albicans) populations, which all decreased by 100% in 1 min [132]. HOCl (~95%) is the main compound of the active chlorine family in SAEW, which is considered to be the cause of microbial inactivation [133]. SAEW with a neutralized pH has attracted more and more attention as an antibacterial solution. SAEW may be a promising novel clinical disinfectant that may be considered as an alternative to traditional alcohol-based hand sanitizer [40,134].

7.3. Oral Hygiene

The dental community has long sought for appropriate antibacterial products to try to control and prevent the proliferation of oral microbiome, especially during dental surgery when host barrier function is often impaired. Microorganisms related to oral hygiene include Streptococcus salivarius, Staphylococcus aureus, Lactobacillus casei, Aggregatibacter actinomycetemcomitans [135,136,137,138]. They found that AEW significantly inhibited the above bacterial growth for 30 secs without negative cytotoxic effects [115]. Hsieh et al. studied the electrolyzed oxidizing (EO) water as a mouthwash against Streptococcus mutans. The results revealed that EOW (125 ppm) showed antimicrobial effectiveness (>99.9%) against S. mutans after soaking treatment for 3 min [139]. The contamination of the dental water unit line is one of the major causes of oral infection [140,141]. A study on the treatment of the oral comprehensive treatment station containing mouthwash and pipe water in hospitals by SAEW treatment has been reported. The qualified rate of water sanitation quality in the water treatment channel increased from 8.85 to 49.15 % [120]. Nakano et al. also reported that there was little negative effects concerning the use of SAEW for the water line of dental units during seven years of clinical trials [142].

7.4. Environmental Decontamination

Experts generally agree that the daily careful cleaning and/or disinfection of environmental surfaces is an essential way to prevent hospital infection [143]. The potential use of EW in the disinfection of inanimate surfaces have been evaluated experimentally [118,144,145]. Meakin et al. revealed that EW exerts a more effective bacterial kill on door hand, lavatory and seat compared to quaternary ammonium disinfectant [146].

8. Future Perspectives

The COVID-19 pandemic has placed an immense burden on healthcare systems and economies around the world. At the time of the study, there was no effective approved vaccine and drug against SARS-CoV-2 available. With increasing hygiene and safety challenges, electrolyzed water holds a potential significance for clinical fields since disinfecting is a critical step during cutting off route transmission [147]. Researchers reported that EW was effective at inactivating SARS-CoV-2, porcine reproductive and respiratory syndrome virus (PRRSV), pseudorabies virus (PRV), foot-and-mouth disease virus (FMDV), Newcastle disease virus [24,148,149,150]. Microorganisms can spread from their source to new hosts through direct or indirect contact, in the air, or through vectors [151].
All the EW exhibits strong antimicrobial efficacy in different fields such as food and hard surface as well as agriculture, medical, and dentistry without irritation [144]. EW has been approved by the Japanese, US, and Chinese regulations as a perfect substitute for harmful chemicals and as a novel sustainable and eco-friendly solution for use in the hospitals and at home. In recent years, a continuous growth trend of commercialization of EW has been observed throughout the world. Given the importance of EW, many companies are scrambling to establish and start producing EW products such as Clortech®, Avenova®, Ecasol™, MicroSafe® and Microcyn®. These companies claim to produce EW-based products that have a remarkable antimicrobial effect, while being safe to use around the nose, mouth, and eyes. However, the limitation of EW is that it has not been widely studied, notably for efficacy against multidrug- and extensively drug-resistant Gram-negative bacteria according with World Health Organization priority pathogens list.
SAEW is the most studied EW and has shown its pH-neutral properties. HOCl was found to be nonirritating and non-sensitizing in various animal safety models. The composition of SAEW solution is relatively simple, and once it becomes exposed to the air, the active ingredients will decompose and its sanitizing efficacy drops [152]. Researchers are constantly exploring the mechanism of the EW antimicrobial effect and developing an advanced and dynamic EW production system that is capable of overcoming all the current limitations. In the near future, this powerful lack of antimicrobial resistance and safety makes SAEW a particularly attractive option for surgical wound site antimicrobial activity, especially in cosmetic, eye care and private women’s care.

9. Conclusions

EW is an effective disinfectant, with several advantages such as on-the-spot, cheap, environmentally friendly and safety production. Nowadays, with the development of a novel popular type of SAEW, some limitations have been resolved. It has been reported that SAEW does not irritate the hands, skin, and mucous membranes, and causes no safety issues from Cl2 off-gassing. It recently emerged with great potential for clinical applications. However, the antimicrobial effect of EW is influenced by the presence of organic matter, water pollutants, and the hardness of the product. Therefore, a dynamic and advanced EW production system or the hurdle technology of combing with multiple technologies-based EW that are able to overcome currently limitations. These may expand the use of EW in clinical applications.

Author Contributions

P.Y.: writing, original draft preparation, E.B.-M.D.: revision and formatting, D.-H.O.: supervision, conceptualization. All authors have read and agreed to the published version of the manuscript.

Funding

This work was supported by a grant from the Brain Korea (BK) 21 Plus Project (Grant No. 22A20153713433) Funded by the Korean Government, Republic of Korea.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Yeshambel, A.; Endalamaw, A.; Belay, D.M.; Mekonen, D.K.; Birhan, B.M.; Bayih, W.A. Healthcare-associated infection and its determinants in Ethiopia: A systematic review and meta-analysis. PLoS ONE 2020, 15, e0241073. [Google Scholar] [CrossRef]
  2. Weiner-Lastinger, L.M.; Abner, S.; Edwards, J.R.; Kallen, A.J.; Karlsson, M.; Magill, S.S.; Pollock, D.; See, I.; Soe, M.M.; Walters, M.S.; et al. Antimicrobial-resistant pathogens associated with adult healthcare-associated infections: Summary of data reported to the National Healthcare Safety Network, 2015–2017. Infect. Control Hosp. Epidemiol. 2019, 41, 1–18. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  3. Savetamal, A. Infection in Elderly Burn Patients: What Do We Know? Surg. Infect. 2020, 21. [Google Scholar] [CrossRef]
  4. Chyderiotis, S.; Legeay, C.; Verjat-Trannoy, D.; Le Gallou, F.; Astagneau, P.; Lepelletier, D. New insights on antimi-crobial efficacy of copper surfaces in the healthcare environment: A systematic review. Clin. Microbiol. Infec. 2018, 24, 1130–1138. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  5. Habibi, A.; Safaiefarahani, B. Indoor Damp Surfaces Harbor Molds with Clinical Significance. Curr. Med. Mycol. 2018, 4, 1–9. [Google Scholar] [CrossRef]
  6. Edmiston, C.E.; McBain, A.J.; Kiernan, M.; Leaper, D.J. A narrative review of microbial biofilm in postoperative surgical site infections: Clinical presentation and treatment. J. Wound Care 2016, 25, 693–702. [Google Scholar] [CrossRef]
  7. Iskandar, K.; Sartelli, M.; Tabbal, M.; Ansaloni, L.; Baiocchi, G.L.; Catena, F.; Coccolini, F.; Haque, M.; Labricciosa, F.M.; Moghabghab, A.; et al. Highlighting the gaps in quantifying the economic burden of surgical site infections associated with antimicrobial-resistant bacteria. World J. Emerg. Surg. 2019, 14, 1–14. [Google Scholar] [CrossRef] [Green Version]
  8. Stevens, D.L. Treatments for skin and soft-tissue and surgical site infections due to MDR Gram-positive bacteria. J. Infect. 2009, 59, S32–S39. [Google Scholar] [CrossRef]
  9. Gomila, A.; Carratalà, J.; Badia, J.M.; Camprubí, D.; Piriz, M.; Shaw, E.; Diaz-Brito, V.; Espejo, E.; Nicolas, C.; Brugués, M. Preoperative oral antibiotic prophylaxis reduces Pseudomonas aeruginosa surgical site infections after elective colorectal surgery: A multicenter prospective cohort study. BMC Infect. Dis. 2018, 18, 507. [Google Scholar] [CrossRef]
  10. Lim, S.L.; Ong, K.C.B.; Chan, Y.H.; Loke, W.C.; Ferguson, M.; Daniels, L. Malnutrition and its impact on cost of hos-pitalization, length of stay, readmission and 3-year mortality. Clin. Nutr. 2012, 31, 345–350. [Google Scholar] [CrossRef] [Green Version]
  11. Lingsma, H.F.; Bottle, A.; Middleton, S.; Kievit, J.; Steyerberg, E.W.; Marang-Van De Mheen, P.J. Evaluation of hospital outcomes: The relation between length-of-stay, readmission, and mortality in a large international administrative database. BMC Health Serv. Res. 2018, 18, 116. [Google Scholar] [CrossRef] [Green Version]
  12. Jamal, M.; Ahmad, W.; Andleeb, S.; Jalil, F.; Imran, M.; Nawaz, M.A.; Hussain, T.; Ali, M.; Rafiq, M.; Kamil, M.A. Bacterial biofilm and associated infections. J. Chin. Med. Assoc. 2018, 81, 7–11. [Google Scholar] [CrossRef]
  13. Song, X.; Vossebein, L.; Zille, A. Efficacy of disinfectant-impregnated wipes used for surface disinfection in hospitals: A review. Antimicrob. Resist. Infect. Control 2019, 8, 1–14. [Google Scholar] [CrossRef] [Green Version]
  14. Klemeš, J.J.; Fan, Y.V.; Jiang, P. The energy and environmental footprints of COVID-19 fighting measures-PPE, dis-infection, supply chains. Energy 2020, 211, 118701. [Google Scholar] [CrossRef]
  15. Wang, J.; Shen, J.; Ye, D.; Yan, X.; Zhang, Y.; Yang, W.; Li, X.; Wang, J.; Zhang, L.; Pan, L. Disinfection technology of hospital wastes and wastewater: Suggestions for disinfection strategy during coronavirus Disease 2019 (COVID-19) pandemic in China. Environ. Pollut. 2020, 262, 114665. [Google Scholar] [CrossRef]
  16. Stoica, M. Sustainable Sanitation in the Food Industry. In Sustainable Food Systems from Agriculture to Industry; Elsevier: Amsterdam, The Netherlands, 2018; pp. 309–339. [Google Scholar]
  17. Sharma, A.; Das, P.; Buschmann, M.; Gilbert, J.A. The Future of Microbiome-Based Therapeutics in Clinical Applications. Clin. Pharmacol. Ther. 2020, 107, 123–128. [Google Scholar] [CrossRef]
  18. Goh, C.F.; Ming, L.C.; Wong, L.C. Dermatologic reactions to disinfectant use during the COVID-19 pandemic. Clin. Dermatol. 2020. [Google Scholar] [CrossRef]
  19. Rahman, S.; Khan, I.; Oh, D.-H. Electrolyzed Water as a Novel Sanitizer in the Food Industry: Current Trends and Future Perspectives. Compr. Rev. Food Sci. Food Saf. 2016, 15, 471–490. [Google Scholar] [CrossRef] [Green Version]
  20. Arya, R.; Bryant, M.; Degala, H.L.; Mahapatra, A.K.; Kannan, G. Effectiveness of a low-cost household electrolyzed water generator in reducing the populations of Escherichia coli K12 on inoculated beef, chevon, and pork surfaces. J. Food Process. Preserv. 2018, 42, e13636. [Google Scholar] [CrossRef]
  21. Veasey, S.; Muriana, P.M. Evaluation of electrolytically-generated hypochlorous acid (‘electrolyzed water’) for sanitation of meat and meat-contact surfaces. Foods 2016, 5, 42. [Google Scholar] [CrossRef] [Green Version]
  22. Graça, A.; Santo, D.; Quintas, C.; Nunes, C. Growth of Escherichia coli, Salmonella enterica and Listeria spp., and their inactivation using ultraviolet energy and electrolyzed water, on ‘Rocha’ fresh-cut pears. Food Control 2017, 77, 41–49. [Google Scholar] [CrossRef]
  23. Xuan, X.; Ling, J. Generation of Electrolyzed Water. In Electrolyzed Water in Food: Fundamentals and Applications; Springer Science and Business Media LLC: Cham, Switzerland, 2019; pp. 1–16. [Google Scholar]
  24. Takeda, Y.; Uchiumi, H.; Matsuda, S.; Ogawa, H. Acidic electrolyzed water potently inactivates SARS-CoV-2 de-pending on the amount of free available chlorine contacting with the virus. Biochem. Bioph. Res. Commun. 2020, 530, 1–3. [Google Scholar] [CrossRef]
  25. Izumi, H.; Inoue, A. Viability of sublethally injured coliform bacteria on fresh-cut cabbage stored in high CO2 atmospheres following rinsing with electrolyzed water. Int. J. Food Microbiol. 2018, 266, 207–212. [Google Scholar] [CrossRef]
  26. Hyun-Ji, K.; Tango, C.N.; Ramachandran, C.; Deog-Hwan, O. Sanitization Efficacy of Slightly Acidic Electrolyzed Water against pure cultures of Escherichia coli, Salmonella enterica, Typhimurium, Staphylococcus aureus and Bacillus cereus spores, in Comparison with Different Water Hardness. Sci. Rep. 2019, 9, 1–14. [Google Scholar]
  27. Lemos, J.G.; Stefanello, A.; Bernardi, A.O.; Garcia, M.V.; Magrini, L.N.; Cichoski, A.J.; Wagner, R.; Copetti, M.V. Antifungal efficacy of sanitizers and electrolyzed waters against toxigenic Aspergillus. Food Res. Int. 2020, 137, 109451. [Google Scholar] [CrossRef]
  28. Salisbury, A.-M.; Percival, S.L. The Efficacy of an Electrolysed Water Formulation on Biofilms. In Neurotransmitter Interactions and Cognitive Function; Springer Science and Business Media LLC: Cham, Switzerland, 2018; pp. 1–8. [Google Scholar]
  29. Eftekharizadeh, F.; Dehnavieh, R.; Hekmat, S.N.; Mehrolhassani, M.H. Health technology assessment on super oxidized water for treatment of chronic wounds. Med. J. Islamic Repub. Iran 2016, 30, 384. [Google Scholar]
  30. Samara, F.; Badran, R.; Dalibalta, S. Are Disinfectants for the Prevention and Control of COVID-19 Safe? Health Secur. 2020, 18, 496–498. [Google Scholar] [CrossRef]
  31. Supardi, E.; Yusuf, S.; Massi, M.N.; Haeruddin, H. Evaluation of different type of electrolyzed water against bacterial colonization of diabetic foot ulcers: Study in vitro. Med. Clínica Práctica 2020, 3, 100090. [Google Scholar] [CrossRef]
  32. Chittoria, R.K.; Yootla, M.; Sampatrao, L.; Raman, S.V. The role of super oxidized solution in the management of diabetic foot ulcer: Our experience. Nepal Med. Coll. J. 2007, 9, 125–128. [Google Scholar]
  33. Bongiovanni, C.M. Effects of Hypochlorous Acid Solutions on Venous Leg Ulcers (VLU): Experience With 1249 VLUs in 897 Patients. J. Am. Coll. Clin. Wound Spéc. 2016, 6, 32–37. [Google Scholar] [CrossRef] [Green Version]
  34. Thekdi, P.I.; Bathla, V.; Koradi, P.; Jhala, D.; Patel, D. A study on newer dressing materials versus conventional dressing materials in ulcer healing. Int. Surg. J. 2016, 3, 108–112. [Google Scholar] [CrossRef]
  35. Hopkins, J. Electrolyzed water treatment for feminine hygiene. Google Patents US20060275502A1, 7 December 2006. [Google Scholar]
  36. Morris, C.D.; Stone, J.K. Method for remediating mold and mildew using acidic electrolyzed water. U.S. Patent 7445800, 4 November 2008. [Google Scholar]
  37. Jo, H.-Y.; Tango, C.N.; Oh, D.-H. Influence of different organic materials on chlorine concentration and sanitization of slightly acidic electrolyzed water. LWT 2018, 92, 187–194. [Google Scholar] [CrossRef]
  38. Xuan, X.; Wang, M.; Ahn, J.; Ma, Y.; Chen, S.; Ye, X.; Liu, D.; Ding, T. Storage Stability of Slightly Acidic Electrolyzed Water and Circulating Electrolyzed Water and Their Property Changes after Application. J. Food Sci. 2016, 81, E610–E617. [Google Scholar] [CrossRef]
  39. Khan, I.; Tango, C.N.; Miskeen, S.; Lee, B.H.; Oh, D.-H. Hurdle technology: A novel approach for enhanced food quality and safety-A review. Food Control 2017, 73, 1426–1444. [Google Scholar] [CrossRef]
  40. Almås, G.H. Acetic acid and hypochlorous acid compositions for treatment of skin trauma. U.S. Patent Application 15/852603, 2018. [Google Scholar]
  41. Almås, G.H. Compositions and methods for treating biofilms without inducing antimicrobial resistance. U.S. Patent Application 16/672393, 2020. [Google Scholar]
  42. Oh, D.-H.; Khan, I.; Tango, C.N. Hurdle Enhancement of Electrolyzed Water with Other Techniques. In Electrolyzed Water in Food: Fundamentals and Applications; Springer Science and Business Media LLC: Cham, Switzerland, 2019; pp. 231–260. [Google Scholar]
  43. Zhiznin, S.; Timokhov, V.; Gusev, A. Economic aspects of nuclear and hydrogen energy in the world and Russia. Int. J. Hydrog. Energy 2020, 45, 31353–31366. [Google Scholar] [CrossRef]
  44. Forghani, F. Application of Electrolyzed Water in Agriculture. In Electrolyzed Water in Food: Fundamentals and Applications; Springer Science and Business Media LLC: Cham, Switzerland, 2019; pp. 223–230. [Google Scholar]
  45. Zheng, W.; Li, Z.; Shah, S.B.; Li, B. Removal of ammonia and airborne culturable bacteria by proof-of-concept wind-break wall with slightly acidic electrolyzed water spray for a layer breeding house. Appl. Eng. Agric. 2016, 32, 393–399. [Google Scholar]
  46. Graça, A.; Santo, D.; Pires-Cabral, P.; Quintas, C. The effect of UV-C and electrolyzed water on yeasts on fresh-cut apple at 4 °C. J. Food Eng. 2020, 282, 110034. [Google Scholar] [CrossRef]
  47. Hakim, H.; Alam, S.; Sangsriratanakul, N.; Nakajima, K.; Kitazawa, M.; Ota, M.; Toyofuku, C.; Yamada, M.; Thammakarn, C.; Shoham, D.; et al. Inactivation of bacteria on surfaces by sprayed slightly acidic hypochlorous acid water: In vitro experiments. J. Vet. Med. Sci. 2016, 78, 1123–1128. [Google Scholar] [CrossRef] [Green Version]
  48. Al-Haq, M.I.; Sugiyama, J.; Isobe, S. Applications of Electrolyzed Water in Agriculture & Food Industries. Food Sci. Technol. Res. 2005, 11, 135–150. [Google Scholar] [CrossRef] [Green Version]
  49. Shiroodi, S.G.; Ovissipour, M. Electrolyzed Water Application in Fresh Produce Sanitation. In Postharvest Disinfection of Fruits and Vegetables; Elsevier: Amsterdam, The Netherlands, 2018; pp. 67–89. [Google Scholar]
  50. Shirahata, S.; Hamasaki, T.; Teruya, K. Advanced research on the health benefit of reduced water. Trends Food Sci. Technol. 2012, 23, 124–131. [Google Scholar] [CrossRef] [Green Version]
  51. U.S. Food & Drug Administration. Environmental Assessment for Food Contact Notification FCN 1811; U.S. Food & Drug Administration: Silver Spring, MD, USA, 2017. Available online: https://www.fda.gov/food/environmental-decisions/environmental-decision-memo-food-contact-notification-no-1811 (accessed on 1 October 2017).
  52. Rahman, S.; Ding, T.; Oh, D.-H. Effectiveness of low concentration electrolyzed water to inactivate foodborne pathogens under different environmental conditions. Int. J. Food Microbiol. 2010, 139, 147–153. [Google Scholar] [CrossRef]
  53. Ding, T.; Oh, D.-H.; Liu, D. Electrolyzed Water in Food: Fundamentals and Applications; Springer: Berlin/Heidelberg, Germany, 2019. [Google Scholar]
  54. Naito, Y.; Higashimura, Y.; Baba, Y.; Inoue, R.; Takagi, T.; Uchiyama, K.; Mizushima, K.; Hirai, Y.; Ushiroda, C.; Tanaka, Y. Effects of molecular hydrogen-dissolved alkaline electrolyzed water on intestinal environment in mice. Med. Gas. Res. 2018, 8, 6–11. [Google Scholar] [CrossRef] [Green Version]
  55. Kitaori, N.; Uno, M.; Nishiki, Y.; Furuta, T. Method of sterilization and electrolytic water ejecting apparatus. U.S. Patent 7,887, 679, 15 February 2011. [Google Scholar]
  56. Kim, E.S. Electrolysis apparatus capable of producing disinfectant or cleaning agent, and electrolysis method therefor. U.S. Pat. Appl. 16/569, 153, 2020. [Google Scholar]
  57. Liang, D.; Wang, Q.; Zhao, D.; Han, X.; Hao, J. Systematic application of slightly acidic electrolyzed water (SAEW) for natural microbial reduction of buckwheat sprouts. LWT 2019, 108, 14–20. [Google Scholar] [CrossRef]
  58. Zheng, W.; Xie, C.; Liang, J.; Yu, Q.-D.; Bai, D.; Huang, J. Effects of weak acidic electrolytic water ice and modified packaging on shrimp quality of Litopenaeus vannamei. Sci. Technol. Food Ind. 2018, 34. Available online: http://en.cnki.com.cn/Article_en/CJFDTotal-REEF201704010.htm (accessed on 1 November 2020).
  59. Rivera-Garcia, A.; Santos-Ferro, L.; Ramirez-Orejel, J.C.; Agredano-Moreno, L.T.; Jimenez-Garcia, L.F.; Pa-ez-Esquiliano, D.; Andrade-Esquivel, E.; Cano-Buendia, J.A. The effect of neutral electrolyzed water as a disinfectant of eggshells artificially contaminated with Listeria monocytogenes. Food Sci. Nutr. 2019, 7, 2252–2260. [Google Scholar] [CrossRef] [Green Version]
  60. Naka, A.; Yakubo, M.; Nakamura, K.; Kurahashi, M. Effectiveness of slightly acidic electrolyzed water on bacteria reduction: In vitro and spray evaluation. PeerJ 2020, 8, e8593. [Google Scholar] [CrossRef] [Green Version]
  61. Zhang, C.; Zhang, Y.; Zhao, Z.; Liu, W.; Chen, Y.; Yang, G.; Xia, X.; Cao, Y. The application of slightly acidic electrolyzed water in pea sprout production to ensure food safety, biological and nutritional quality of the sprout. Food Control 2019, 104, 83–90. [Google Scholar] [CrossRef]
  62. Mansur, A.R.; Oh, D.-H. Modeling the Growth of Epiphytic Bacteria on Kale Treated by Thermosonication Combined with Slightly Acidic Electrolyzed Water and Stored under Dynamic Temperature Conditions. J. Food Sci. 2016, 81, M2021–M2030. [Google Scholar] [CrossRef]
  63. Bansal, V.; Prasad, P.; Mehta, D.; Siddiqui, M.W. Ultrasound Techniques in Postharvest Disinfection of Fruits and Vegetables; Elsevier: Amsterdam, The Netherlands, 2018; pp. 159–177. [Google Scholar]
  64. Zhang, J.; Yang, H.; Chan, J.Z.Y. Development of Portable Flow-Through Electrochemical Sanitizing Unit to Generate Near Neutral Electrolyzed Water. J. Food Sci. 2018, 83, 780–790. [Google Scholar] [CrossRef]
  65. Xuan, X.T.; Fan, Y.F.; Ling, J.G.; Hu, Y.; Liu, D.H.; Chen, S.G.; Ye, X.Q.; Ding, T. Preservation of squid by slightly acidic electrolyzed water ice. Food Control 2017, 73, 1483–1489. [Google Scholar] [CrossRef]
  66. Da Cruz Nizer, W.S.; Inkovskiy, V.; Overhage, J. Surviving reactive chlorine stress: Responses of gram-negative bacteria to hypochlorous acid. Microorganisms 2020, 8, 1220. [Google Scholar] [CrossRef]
  67. Ding, T.; Xuan, X.T.; Li, J.; Chen, S.; Liu, D.H.; Ye, X.; Shi, J.; Xue, S.J. Disinfection efficacy and mechanism of slightly acidic electrolyzed water on Staphylococcus aureus in pure culture. Food Control 2016, 60, 505–510. [Google Scholar] [CrossRef]
  68. Severing, A.L.; Rembe, J.D.; Koester, V.; Stuermer, E.K. Safety and efficacy profiles of different commercial sodium hypochlorite/hypochlorous acid solutions (NaClO/HClO): Antimicrobial efficacy, cytotoxic impact and physicochemical parametersin vitro. J. Antimicrob. Chemother. 2019, 74, 365–372. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  69. Busch, M.; Simic, N.; Ahlberg, E. Exploring the mechanism of hypochlorous acid decomposition in aqueous solutions. Phys. Chem. Chem. Phys. 2019, 21, 19342–19348. [Google Scholar] [CrossRef]
  70. Hung, Y.C.; Waters, B.W.; Yemmireddy, V.K.; Huang, C.H. pH effect on the formation of THM and HAA disinfection byproducts and potential control strategies for food processing. J. Integr. Agric. 2017, 16, 2914–2923. [Google Scholar] [CrossRef]
  71. Sam, C.H.; Lu, H.K. The role of hypochlorous acid as one of the reactive oxygen species in periodontal disease. J. Dent. Sci. 2009, 4, 45–54. [Google Scholar] [CrossRef] [Green Version]
  72. Medina-Gudiño, J.; Rivera-Garcia, A.; Santos-Ferro, L.; Ramirez-Orejel, J.C.; Agredano-Moreno, L.T.; Jimenez-Garcia, L.F.; Paez-Esquiliano, D.; Martinez-Vidal, S.; Andrade-Esquivel, E.; Cano-Buendia, J.A. Analysis of Neutral Electrolyzed Water anti-bacterial activity on contaminated eggshells with Salmonella enterica or Escherichia coli. Int. J. Food Microbiol. 2020, 320, 108538. [Google Scholar] [CrossRef]
  73. Liao, L.B.; Chen, W.M.; Xiao, X.M. The generation and inactivation mechanism of oxidation–reduction potential of electrolyzed oxidizing water. J. Food Eng. 2007, 78, 1326–1332. [Google Scholar] [CrossRef]
  74. Hsu, S.-Y. Effects of flow rate, temperature and salt concentration on chemical and physical properties of electrolyzed oxidizing water. J. Food Eng. 2005, 66, 171–176. [Google Scholar] [CrossRef]
  75. Hsu, S.-Y. Effects of water flow rate, salt concentration and water temperature on efficiency of an electrolyzed oxidizing water generator. J. Food Eng. 2003, 60, 469–473. [Google Scholar] [CrossRef]
  76. Huang, Y.R.; Hung, Y.C.; Hsu, S.Y.; Huang, Y.W.; Hwang, D.F. Application of electrolyzed water in the food in-dustry. Food Control 2008, 19, 329–345. [Google Scholar] [CrossRef]
  77. Possas, A.; Pérez-Rodríguez, F.; Tarlak, F.; García-Gimeno, R.M. Quantifying and modelling the inactivation of Listeria monocytogenes by electrolyzed water on food contact surfaces. J. Food Eng. 2021, 290, 110287. [Google Scholar] [CrossRef]
  78. Thorn, R.M.S.; Lee, S.W.H.; Robinson, G.M.; Greenman, J.; Reynolds, D.M. Electrochemically activated solutions: Evidence for antimicrobial efficacy and applications in healthcare environments. Eur. J. Clin. Microbiol. Infect. Dis. 2011, 31, 641–653. [Google Scholar] [CrossRef]
  79. Al-Qadiri, H.M.; Smith, S.; Sielaff, A.C.; Govindan, B.N.; Ziyaina, M.; Al-Alami, N.; Rasco, B. Bactericidal activity of neutral electrolyzed water against Bacillus cereus and Clostridium perfringens in cell suspensions and artificially inoculated onto the surface of selected fresh produce and polypropylene cutting boards. Food Control 2019, 96, 212–218. [Google Scholar] [CrossRef]
  80. Dragana, O.; Richard, K.A.; Holdsworth, S.R. Neutrophil-mediated regulation of innate and adaptive immunity: The role of myeloperoxidase. J. Immunol. Res. 2016, 6, 1–11. [Google Scholar]
  81. Hricova, D.; Stephan, R.; Zweifel, C. Electrolyzed water and its application in the food industry. J. Food Protect. 2008, 71, 1934–1947. [Google Scholar] [CrossRef] [PubMed]
  82. Dewi, F.R.; Stanley, R.; Powell, S.M.; Burke, C.M. Application of electrolysed oxidising water as a sanitiser to extend the shelf-life of seafood products: A review. J. Food Sci. Technol. 2017, 54, 1321–1332. [Google Scholar] [CrossRef]
  83. Park, H.; Puligundla, P.; Mok, C. Microbial Decontamination of Mung Bean Sprouts Using Electrolyzed Water and Its Effects on The Physicochemical and Sensory Properties of The Sprouts. Chiang Mai J. Sci. 2020, 47, 28–38. [Google Scholar]
  84. Gómez-López, V.M.; Gil, M.I.; Allende, A. A novel electrochemical device as a disinfection system to maintain water quality during washing of ready to eat fresh produce. Food Control 2017, 71, 242–247. [Google Scholar] [CrossRef]
  85. Block, Z.; Eyles, A.; Corkrey, R.; Stanley, R.; Ross, T.; Kocharunchitt, C. Effect of Storage Conditions on Shelf Stability of Undiluted Neutral Electrolyzed Water. J. Food Protect. 2020, 83, 1838–1843. [Google Scholar] [CrossRef]
  86. Feliziani, E.; Lichter, A.; Smilanick, J.L.; Ippolito, A. Disinfecting agents for controlling fruit and vegetable diseases after harvest. Postharvest Biol. Technol. 2016, 122, 53–69. [Google Scholar] [CrossRef]
  87. Xiao, R.; Liu, K.; Bai, L.; Minakata, D.; Seo, Y.; Göktaş, R.K.; Dionysiou, D.D.; Tang, C.-J.; Wei, Z.; Spinney, R. Inactivation of pathogenic microorganisms by sulfate radical: Present and future. Chem. Eng. J. 2019, 371, 222–232. [Google Scholar] [CrossRef]
  88. Akbulut, M.B.; Eldeniz, A.U. In vitro antimicrobial activity of different electrochemically-activated solutions on enterococcus faecalis. Eur. Oral Res. 2019, 53, 44. [Google Scholar] [CrossRef] [PubMed]
  89. Fukuzaki, S. Mechanisms of Actions of Sodium Hypochlorite in Cleaning and Disinfection Processes. Biocontrol Sci. 2006, 11, 147–157. [Google Scholar] [CrossRef] [PubMed]
  90. Block, M.S.; Rowan, B.G. Hypochlorous acid–a review. J. Oral Maxil. Surg. 2020, 78, 1461–1466. [Google Scholar] [CrossRef] [PubMed]
  91. Tang, W.; Zeng, X.; Zhao, Y.; Ye, G.; Gui, W.; Ni, Y. Disinfection effect and its mechanism of electrolyzed oxidizing water on spores of Bacillus subtilis var. niger. Food Sci. Biotechnol. 2011, 20, 889–895. [Google Scholar] [CrossRef]
  92. Zhao, L. Electrolysed Water Combined With Levulinic Acid and Ultrasound for Sanitisation and Its Antimicrobial Mechanism. Master’s Thesis, National University of Singapore, Singapore, 2017. [Google Scholar]
  93. Nybo, T.; Dieterich, S.; Gamon, L.F.; Chuang, C.Y.; Hammer, A.; Hoefler, G.; Malle, E.; Rogowska-Wrzesinska, A.; Davies, M.J. Chlorination and oxidation of the extracellular matrix protein laminin and basement membrane extracts by hypochlorous acid and myeloperoxidase. Redox Biol. 2019, 20, 496–513. [Google Scholar] [CrossRef]
  94. Memar, M.Y.; Ghotaslou, R.; Samiei, M.; Adibkia, K. Antimicrobial use of reactive oxygen therapy: Current insights. Infect. Drug Resist. 2018, 11, 567–576. [Google Scholar] [CrossRef] [Green Version]
  95. National Criterion of China. Hygienic Requirement for Disinfectants with Chlorine GB/T 36758-2018; National Criterion of China. Available online: http://openstd.samr.gov.cn/bzgk/gb/newGbInfo?hcno=CFCB58954F3CA1C01908B0407FF97D8E (accessed on 1 April 2019).
  96. National Criterion of China. Genaral Requirements for Disfectant of Mucous Membrane GB/T 27954-2020; National Criterion of China. Available online: http://std.samr.gov.cn/gb/search/gbDetailed?id=A327FCEA3049B9B7E05397BE0A0A8A97 (accessed on 1 November 2020).
  97. Fukuyama, T.; Martel, B.C.; Linder, K.E.; Ehling, S.; Ganchingco, J.R.; Bäumer, W. Hypochlorous acid is antipruritic and anti-inflammatory in a mouse model of atopic dermatitis. Clin. Exp. Allergy 2017, 48, 78–88. [Google Scholar] [CrossRef]
  98. Alimi, H. Method of using oxidative reductive potential water solution in dental applications. U.S. Patent 9498548, 22 November 2016. [Google Scholar]
  99. Arai, N.; Hayashi, N. Washing machine, electrolyte for generating electrolyzed water, and electrolyzed water for rinse. U.S. Patent Application 15/511754, 2017. [Google Scholar]
  100. Garcia, J.P.; Michel, B.A.P.; Moctezuma, M.V.; Enciso, I.D. Neutral Electrolyzed Water and Uses Thereof. U.S. Patent Application 15/791927, 2018. [Google Scholar]
  101. Ministry of Health, Labour and Welfare. Advanced Acid Electrolyzed Water Generator; Ministry of Health, Labour and Welfare: Tokyo, Japan, 2005. [Google Scholar]
  102. Ministry of Health, Labour and Welfare. Guidelines for Standardization of Cleaning and Disinfection of Digestive Endoscopy; Ministry of Health, Labour and Welfare: Tokyo, Japan, 2018. [Google Scholar]
  103. Ministry of Health, Labour and Welfare. The Contents of the Consideration (Draft) Which Should be Provided with Regard to the Material Specified as a Specified Agricultural Chemical (Specified Control Material); Ministry of Health, Labour and Welfare: Tokyo, Japan, 2003. [Google Scholar]
  104. European commission. Expert Group for Technical Advice on Organic Production; European Commission: Brussels, Belgium, 2016; Available online: http://www.envirolyte.com/Expert-Group.pdf (accessed on 1 November 2020).
  105. Herruzo, R.; Herruzo, I. Antimicrobial efficacy of a very stable hypochlorous acid formula compared with other anti-septics used in treating wounds: In-vitro study on micro-organisms with or without biofilm. J. Hosp. Infect. 2020, 105, 289–294. [Google Scholar] [CrossRef]
  106. Stroman, D.W.; Mintun, K.; Epstein, A.B.; Brimer, C.M.; Patel, C.R.; Branch, J.D.; Najafi-Tagol, K. Reduction in bacterial load using hypochlorous acid hygiene solution on ocular skin. Clin. Ophthalmol. 2017, 11, 707. [Google Scholar] [CrossRef] [Green Version]
  107. Hiebert, 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, e32. [Google Scholar] [PubMed]
  108. Sasai-Takedatsu, M.; Kojima, T.; Yamamoto, A.; Hattori, K.; Yoshijima, S.; Taniuchi, S.; Namura, S.; Akamatsu, H.; Horio, T.; Kobayashi, Y. Reduction of Staphylococcus aureus in atopic skin lesions with acid electrolytic water-a new therapeutic strategy for atopic dermatitis. Allergy 1997, 52, 1012–1016. [Google Scholar] [CrossRef] [PubMed]
  109. You, H.S.; Fadriquela, A.; Sajo, M.E.J.; Bajgai, J.; Ara, J.; Kim, C.S.; Kim, S.-K.; Oh, J.R.; Shim, K.Y.; Lim, H.K. Wound healing effect of slightly acidic electrolyzed water on cutaneous wounds in hairless mice via immune-redox modulation. Biol. Pharm. Bull. 2017, 40, 1423–1431. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  110. Kuwabara, M.; Sato, Y.; Ishihara, M.; Takayama, T.; Nakamura, S.; Fukuda, K.; Murakami, K.; Yokoe, H.; Kiyosawa, T. Healing of Pseudomonas aeruginosa-infected wounds in diabetic db/db mice by weakly acidic hypochlorous acid cleansing and silver nanoparticle/chitin-nanofiber sheet covering. Wound Med. 2020, 28, 100183. [Google Scholar] [CrossRef]
  111. Chen, K.K.; Wu, J.H.; Wei, S.I.; Du, J.K. Influence of the acidity of electrolyzed water on the microhardness of inner layer dentin. J. Dent. Sci. 2019, 14, 419–425. [Google Scholar] [CrossRef]
  112. Kiamco, M.M.; Zmuda, H.M.; Mohamed, A.; Call, D.R.; Raval, Y.S.; Patel, R.; Beyenal, H. Hypochlorous-Acid-Generating Electrochemical Scaffold for Treatment of Wound Biofilms. Sci. Rep. 2019, 9, 2683. [Google Scholar] [CrossRef] [Green Version]
  113. Johani, K.; Malone, M.; Jensen, S.O.; Dickson, H.G.; Gosbell, I.B.; Hu, H.; Yang, Q.; Schultz, G.; Vickery, K. Evaluation of short exposure times of antimicrobial wound solutions against microbial biofilms: From in vitro to in vivo. J. Antimicrob. Chemother. 2018, 73, 494–502. [Google Scholar] [CrossRef] [Green Version]
  114. Reis, R.; Sipahi, H.; Dinc, O.; Kavaz, T.; Charehsaz, M.; Dimoglo, A.; Aydın, A. Toxicity, mutagenicity and stability assessment of simply produced electrolyzed water as a wound healing agent in vitro. Hum. Exp. Toxicol. 2020. [Google Scholar] [CrossRef]
  115. Vahabi, S.; Shokri, M.; Lazar, M. Effects of Electrolyzed Water on the Growth of Oral Pathologic Bacteria Species and its Cytotoxic Effects on Fibroblast and Epithelial Cells at Different pH Values. Iran. J. Basic Med. Sci. 2020, 45, 277–285. [Google Scholar]
  116. Ishiyama, K.; Nakamura, K.; Kanno, T.; Niwano, Y. Bactericidal Action of Photodynamic Antimicrobial Chemotherapy (PACT) with Photosensitizers Used as Plaque-Disclosing Agents against Experimental Biofilm. Biocontrol. Sci. 2016, 21, 187–191. [Google Scholar] [CrossRef] [Green Version]
  117. Kubota, A.; Goda, T.; Tsuru, T.; Yonekura, T.; Yagi, M.; Kawahara, H.; Yoneda, A.; Tazuke, Y.; Tani, G.; Ishii, T. 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, 876–879. [Google Scholar] [CrossRef] [PubMed]
  118. Chen, C.J.; Chen, C.C.; Ding, S.J. Effectiveness of hypochlorous acid to reduce the biofilms on titanium alloy sur-faces in vitro. Int. J. Mol. Sci. 2016, 17, 1161. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  119. Lee, S.H.; Choi, B.K. Antibacterial effect of electrolyzed water on oral bacteria. J. Microbiol. 2006, 44, 417–422. [Google Scholar] [PubMed]
  120. Xin, P.J.; Huang, N.; Sun, H.H.; Wang, J.Q.; Su, J. Research for continuous disinfection on the dental unit water lines. Chin. J. Disinfect. 2017, 34, 422–425. [Google Scholar]
  121. Galvin, S.; Boyle, M.; Russell, R.; Coleman, D.; Creamer, E.; O’Gara, J.P.; Fitzgerald-Hughes, D.; Humphreys, H. Evaluation of vaporized hydrogen peroxide, Citrox and pH neutral Ecasol for decontamination of an enclosed area: A pilot study. J. Hosp. Infect. 2012, 80, 67–70. [Google Scholar] [CrossRef]
  122. Kim, S.B. Development of a mouthwash alternative using a low-level hypochlorous acid solution with macroporous platinum electrodes and its application to oral health. Int. J. Clin. Exp. Med. 2016, 9, 21304–21311. [Google Scholar]
  123. Park, G.W.; Boston, D.M.; Kase, J.A.; Sampson, M.N.; Sobsey, M.D. Evaluation of Liquid- and Fog-Based Application of Sterilox Hypochlorous Acid Solution for Surface Inactivation of Human Norovirus. Appl. Environ. Microbiol. 2007, 73, 4463–4468. [Google Scholar] [CrossRef] [Green Version]
  124. Negut, I.; Grumezescu, V.; Grumezescu, A.M. Treatment Strategies for Infected Wounds. Molecules 2018, 23, 2392. [Google Scholar] [CrossRef] [Green Version]
  125. Opneja, A.; Kapoor, S.; Stavrou, E.X. Contribution of platelets, the coagulation and fibrinolytic systems to cutaneous wound healing. Thromb. Res. 2019, 179, 56–63. [Google Scholar] [CrossRef]
  126. Leaper, D.J.; Schultz, G.; Carville, K.; Fletcher, J.; Swanson, T.; Drake, R. Extending the TIME concept: What have we learned in the past 10 years? Int. Wound J. 2012, 9, 1–19. [Google Scholar] [CrossRef]
  127. Joachim, D. Wound cleansing: Benefits of hypochlorous acid. J. Wound Care 2020, 29, S4–S8. [Google Scholar] [CrossRef] [PubMed]
  128. Ben-Nakhi, M.E.; Eltayeb, H.I. First Middle East Experience with Novel Foam Dressing Together with Negative Pres-sure Wound Therapy and Instillation. Cureus 2018, 10, e3415. [Google Scholar] [PubMed] [Green Version]
  129. Tirado-Sánchez, A.; Ponce-Olivera, R.M. Efficacy and tolerance of superoxidized solution in the treatment of mild to moderate inflammatory acne. A double-blinded, placebo- controlled, parallel-group, randomized, clinical trial. J. Dermatol. Treat. 2009, 20, 289–292. [Google Scholar] [CrossRef] [PubMed]
  130. Gold, M.H.; Andriessen, A.; Bhatia, A.C.; Bitter, P., Jr.; Chilukuri, S.; Cohen, J.L.; Robb, C.W. Topical stabilized hypochlorous acid: The future gold standard for wound care and scar management in dermatologic and plastic surgery procedures. J. Cosmet. Dermatol. 2020, 19, 270–277. [Google Scholar] [CrossRef] [PubMed]
  131. Jing, J.L.J.; Yi, T.P.; Bose, R.J.; McCarthy, J.R.; Tharmalingam, N.; Madheswaran, T. Hand Sanitizers: A Review on Formulation Aspects, Adverse Effects, and Regulations. Int. J. Environ. Res. Public Health 2020, 17, 3326. [Google Scholar] [CrossRef] [PubMed]
  132. Sipahi, H.; Reis, R.; Dinc, O.; Kavaz, T.; Dimoglo, A.; Aydın, A. In vitro biocompatibility study approaches to evaluate the safety profile of electrolyzed water for skin and eye. Hum. Exp. Toxicol. 2019, 38, 1314–1326. [Google Scholar] [CrossRef]
  133. Ding, T.; Ge, Z.; Shi, J.; Xu, Y.-T.; Jones, C.L.; Liu, D.-H. Impact of slightly acidic electrolyzed water (SAEW) and ultrasound on microbial loads and quality of fresh fruits. LWT Food Sci. Technol. 2015, 60, 1195–1199. [Google Scholar] [CrossRef]
  134. Almås, G.H.; Bignami, A. Hypochlorous acid preparation with organic acids. U.S. Patent 10029917, 24 July 2018. [Google Scholar]
  135. Dodoo, C.C.; Stapleton, P.; Basit, A.W.; Gaisford, S. The potential of Streptococcus salivarius oral films in the management of dental caries: An inkjet printing approach. Int. J. Pharmaceut. 2020, 591, 119962. [Google Scholar] [CrossRef]
  136. Lin, Y.T.J.; Chou, C.C.; Hsu, C.Y.S. Effects of Lactobacillus casei Shirota intake on caries risk in children. J. Dent. Sci. 2017, 12, 179–184. [Google Scholar] [CrossRef]
  137. Gholizadeh, P.; Pormohammad, A.; Eslami, H.; Shokouhi, B.; Fakhrzadeh, V.; Kafil, H.S. Oral pathogenesis of Aggregatibacter actinomycetemcomitans. Microb. 2017, 113, 303–311. [Google Scholar] [CrossRef]
  138. Ab Malik, N.; Razak, F.A.; Lam, O.L.T.; Jin, L.; Li, L.S.; McGrath, C. Oral Health Interventions Using Chlorhexidine-Effects on the Prevalence of Oral Opportunistic Pathogens in Stroke Survivors: A Randomized Clinical Trial. J. Evid. Based Dent. Pract. 2018, 18, 99–109. [Google Scholar] [CrossRef] [PubMed]
  139. Hsieh, Y.L.; Yao, J.C.; Hsieh, S.C.; Teng, N.C.; Chu, Y.T.; Yu, W.X.; Chen, C.H.; Chang, L.Y.; Huang, C.S.; Lee, T.H.; et al. The In Vivo Toxicity and Antimicrobial Properties for Electrolyzed Oxidizing (EO) Water-Based Mouthwashes. Materials 2020, 13, 4299. [Google Scholar] [CrossRef] [PubMed]
  140. Rossi-Fedele, G.; Doğramacı, E.J.; Steier, L.; De Figueiredo, J.A.P. Some factors influencing the stability of Sterilox®, a superoxidised water. Br. Dent. J. 2011, 210, E23. [Google Scholar] [CrossRef] [PubMed]
  141. Lata, S.; Mohanty, S.K.; Pradhan, P.K.; Patri, G.; Sinha, S.P.; Agrawal, P. Anti bacterial effectiveness of electro-chemically activated (ECA) water as a root canal irrigant-An in-vitro comparative study. J. Clin. Diagn. Res. 2016, 10, ZC138. [Google Scholar] [CrossRef]
  142. Nakano, M.; Takao, A.; Maeda, N.; Hosoya, N. Efficacy of Slightly Acidic Electrolyzed Water against Contamination of Water Line of Dental Units. Nippon Eiseigaku Zasshi (Jpn. J. Hyg.) 2020, 75, 19021. [Google Scholar] [CrossRef]
  143. Boyce, J.M. Modern technologies for improving cleaning and disinfection of environmental surfaces in hospitals. Antimicrob. Resist. Infect. Control 2016, 5, 1–10. [Google Scholar] [CrossRef] [Green Version]
  144. Ni, L.; Zheng, W.; Zhang, Q.; Cao, W.; Li, B. Application of slightly acidic electrolyzed water for decontamination of stainless steel surfaces in animal transport vehicles. Prev. Vet. Med. 2016, 133, 42–51. [Google Scholar] [CrossRef]
  145. Stewart, M.; Bogusz, A.; Hunter, J.; Devanny, I.; Yip, B.; Reid, D.; Robertson, C.; Dancer, S.J. Evaluating Use of Neutral Electrolyzed Water for Cleaning Near-Patient Surfaces. Infect. Control Hosp. Epidemiol. 2014, 35, 1505–1510. [Google Scholar] [CrossRef] [Green Version]
  146. Meakin, N.; Bowman, C.; Lewis, M.; Dancer, S. Comparison of cleaning efficacy between in-use disinfectant and electrolysed water in an English residential care home. J. Hosp. Infect. 2012, 80, 122–127. [Google Scholar] [CrossRef]
  147. Tango, C.N.; Hussain, M.S.; Oh, D.-H. Application of Electrolyzed Water on Environment Sterilization. In Electrolyzed Water in Food: Fundamentals and Applications; Springer Science and Business Media LLC: Cham, Switzerland, 2019; pp. 177–204. [Google Scholar]
  148. Hao, X.; Shen, Z.; Wang, J.; Zhang, Q.; Li, B.; Wang, C.; Cao, W. In vitro inactivation of porcine reproductive and respiratory syndrome virus and pseudorabies virus by slightly acidic electrolyzed water. Vet. J. 2013, 197, 297–301. [Google Scholar] [CrossRef]
  149. Bui, V.N.; Nguyen, K.V.; Pham, N.T.; Bui, A.N.; Imai, K. Potential of electrolyzed water for disinfection of foot-and-mouth disease virus. J. Vet. Med. Sci. 2017, 79, 726–729. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  150. Hakim, H.; Thammakarn, C.; Suguro, A.; Ishida, Y.; Nakajima, K.; Kitazawa, M.; Takehara, K. Aerosol Disinfection Capacity of Slightly Acidic Hypochlorous Acid Water Towards Newcastle Disease Virus in the Air: An In Vivo Experiment. Avian. Dis. 2015, 59, 486–491. [Google Scholar] [CrossRef] [PubMed]
  151. Comunian, S.; Dongo, D.; Milani, C.; Palestini, P. Air Pollution and COVID-19: The Role of Particulate Matter in the Spread and Increase of COVID-19′s Morbidity and Mortality. Int. J. Environ. Res. Public Health 2020, 17, 4487. [Google Scholar] [CrossRef] [PubMed]
  152. Esua, O.J.; Cheng, J.H.; Sun, D.W. Functionalization of water as a nonthermal approach for ensuring safety and quality of meat and seafood products. Crit. Rev. Food Sci. Nutr. 2020, 61, 1–19. [Google Scholar]
Microorganisms 09 00136 g001 550
Figure 1. Application of electrolyzed water (EW) at different pH values in various fields.
Figure 1. Application of electrolyzed water (EW) at different pH values in various fields.
Microorganisms 09 00136 g001
Microorganisms 09 00136 g002 550
Figure 2. Generation of electrolyzed water. (A): alkaline electrolyzed water and acidic electrolyzed water; (B): slightly acidic electrolyzed water. Created with BioRender.com.
Figure 2. Generation of electrolyzed water. (A): alkaline electrolyzed water and acidic electrolyzed water; (B): slightly acidic electrolyzed water. Created with BioRender.com.
Microorganisms 09 00136 g002
Microorganisms 09 00136 g003 550
Figure 3. Factors affecting the decontamination efficacy of electrolyzed water. ACC: available chlorine concentration; ORP: oxidation–reduction potential.
Figure 3. Factors affecting the decontamination efficacy of electrolyzed water. ACC: available chlorine concentration; ORP: oxidation–reduction potential.
Microorganisms 09 00136 g003
Microorganisms 09 00136 g004 550
Figure 4. Model representing the mechanism of electrolyzed water. Created with BioRender.com.
Figure 4. Model representing the mechanism of electrolyzed water. Created with BioRender.com.
Microorganisms 09 00136 g004
Microorganisms 09 00136 g005 550
Figure 5. Model representing the mechanism of electrolyzed water on wounds. Created with BioRender.com.
Figure 5. Model representing the mechanism of electrolyzed water on wounds. Created with BioRender.com.
Microorganisms 09 00136 g005
Table
Table 1. Criteria of EW in different countries.
Table 1. Criteria of EW in different countries.
Japan [101,102,103]The United States [51]EU [104]China [95,96]
AdministrationMinistry of Health, Labor, and WelfareAdministration of US Food and DrugEuropean Commission
Directorate-General for Agriculture and Rural Development		Standardization administration
ApplicationStrong acid electrolyzed water (pH < 2.7):
20–60 ppm: hand washing in operation, cleaning and disinfection of endoscope and food additives.		Poultry Processing FacilitiesBuildings and installations
Aquaculture (only in the absence of animals)		Indoor air environment
General object surface
Medical equipment
Surface of secondary water supply equipment and facilities
Slightly acid electrolyzed water (2.7–5.0):
10–60 ppm: food additives and designation of specified pesticides (specific control materials)		Meat ProcessingIn general agriculture and in organic farming
Plant and animal production
Food processing		Vegetables and fruits
Slightly acid electrolyzed water (ph:5.0–6.0):
10–80 ppm: food additives		Fruit and Vegetable Processing Facilities Fabric
Fish and Seafood Processing Utensils
Processed and Preformed Meat and Poultry Hands
Shell Egg Wash
Organic Production and
Handling		 Skin and mucous membrane
ACC concentrationStrong acid electrolyzed water (ph < 2.7):
20–60 ppm
Slightly acid electrolyzed water (2.7–5.0):
10–60 ppm
Slightly acid electrolyzed water (pH:5.0–6.0):
10–80 ppm		<60 ppm
Organic production and
Handling(≤4 ppm)		Electrolyzed water usually contains 20–60 ppm (hypochlorite and hypochlorous acid, in a pH-dependent equilibrium).Requirement of different application of toxicity
RequirementElectrolyzed water must be decomposed or removed before completion of the final foodThe treatment will be followed by either a 10 min drain step or a potable water rinse to remove Non toxicity
Table
Table 2. Characteristics and parameters of various electrolyzed waters.
Table 2. Characteristics and parameters of various electrolyzed waters.
Type of EWDiaphragm ElectrolyzerElectrolytepHORP (mV)ACC
Acidic electrolyzed water/electrolyzed oxidizing waterTwo-cell chambers /anode
Three-cell chambers/anode		NaCl water (<0.2%)2–2.7>110020–60
Weak acid electrolyzed waterTwo-cell chambers
Three-cell chambers		NaCl water (<0.2%)2.7–5.0-10–60
Slightly acid electrolyzed waterSingle-cell chamber
(without diaphragm)		HCl water (2–6%)/
The mixture water of NaCl and HCl		5–6.585010–80
Neutralized electrolyzed waterSingle-cell unit
(without diaphragm)		NaCl or HCl7–8750–90030–200
Alkaline electrolyzed waterTwo-cell chambers
/cathode		NaCl water10–13−800–90080–100
Table
Table 3. Applications of EW against various microorganisms in clinical infections.
Table 3. Applications of EW against various microorganisms in clinical infections.
ApplicationTargetEW Type
(Product)		Exposure TimeObservations
(log CFU)		ACCpHORP (Mv)Reference
WoundThese comprised
three Gram-positive bacteria (Enterococcus faecium; S. epidermidis and S. aureus);
three Gram-negative bacteria (Morganella morganii; Enterobacter cloacae and P. aeruginosa) and two yeasts (Candida albicans and Torulopsis glabrata).		EW
Clortech®		54.57 log CFU/cm2500--[105]
EyeS. epidermidis colony-forming unitsEW
Avenova®		20>99.5%1004-[106]
WoundX Pseudomonas
Staphylococcus aureus		Slightly acid electrolyzed water (SAEW)
Vashe Wound Solution		-3.78 log/g
4.44 log/g		-5.5-[107]
Atopic dermatitis on skinStaphylococcus aureusAcidic electrolyzed water (AEW)3 min after
spraying (P < 0.05) and after 1 week of skin treatment		3.80 log/cm2-≤2.71000≥[108]
Wound healingHairless mice (wound size)Slightly acid electrolyzed water (SAEW)Hairless mice three times a day for seven daysWound size reduced to 22.4%255.5–6.5800[109]
Wound healingPseudomonas aeruginosa-infected woundsWeakly acidic hypochlorous acidCleansing effects of HOCl and covering with CNFS/Ag NP composites daily for 3 daysWound size reduced to 23%2006.5-[110]
Inner layer dentinThe time dependent microhardness values at 25 μm depthAEW15 min75% decrease492.4-[111]
Wound biofilmsS. aureus biofilms
A. baumannii biofilms
P. aeruginosa biofilms		EW180
120
60		100%
100%
100%		892
524
367		6.0-[112]
Wound biofilmStaphylococcus aureus biofilm in vitro
Pseudomonas aeruginosa biofilm in vitro
Pseudomonas aeruginosa biofilm in an ex vivo porcine skin explant model		Microcyn®154.3 log10 CFU/mL reduction
7 log10 CFU/mL reduction
0.77 log10 CFU /mL reduction		---[113]
Atopic dermatitisNC/Nga mouse model of Atopic dermatitisEWTwice a dayless skin lesions
prevent scratching bouts
nontoxicity		5006.0-[97]
Wound healingCytotoxicity in L929 mice fibroblast cells
Wound healing activity		Strong acid electrolyzed water (StAEW)Scratch assay88.84% wound healing ratio
No mutagenic activity		32.872.41140.67[114]
Oral Pathologic Bacteria SpeciesA. actinomycetemcomitans
S. salivarius
L. casei
S. aureus		AEW0.5100%
99.92%
99.99%
98.04%		-3-[115]
Dental plaque (biofilm)Streptococcus mutans biofilmSIEW 3 log reduction CFU/cm2511.4–11.7−868[116]
Ascetic fluidSurgical site infection including Escherichia coli, Bacteroides fragilis, γ-hemolytic Streptococcus)StAEW-No one infection in 24 patients402.5–2.71000–11000[117]
Titanium alloy surfacesE. coli
P. gingivalis
E. faecalis
S. sanguinis		EW1.5100%
100%
100%
100%		1805.5-[118]
ToothbrushesA.actinomycetemcomitans
F. nucleatum
P. intermedia
P. gingivalis		EW0.511.0–12.4%308.4-[119]
Oral comprehensive treatment tablePseudomonas aeruginosa and Legionella pneumophilaSAEWFlush the oral comprehensive treatment table4.30 log/mL105.5–6.5982[120]
Floor, table, mattress, sheet, blanket, curtainEscherichia coli
Staphylococcus aureus
Enterococcus faecalis
Pseudomonas aeruginosa
Aspergillus fumigatus
Acinetobacter baumannii
Clostridium difficile		Ecasol™1.5 h≥7 log/cm21000Ph neutral-[121]
Oral bacteria strainsPorphyromonas gingivalis
Prevotella intermedia
Prevotella nigrescens
Fusobacterium nucleatum
Streptococcus mutans
Streptococcus sobrinus
Streptococcus gordonii
Streptococcus oralis
Streptococcus salivarius		SAEW1≥99.999%
≥99.999%
≥99.9999%
≥99.9999%
≥99.9999%
≥99.999%
≥99.99%
≥99.99999%
≥99.9999%		3–55–7-[122]
PorousNorovirusesEW103 log/cm22005.5–6.2-[123]
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Share and Cite

MDPI and ACS Style

Yan, P.; Daliri, E.B.-M.; Oh, D.-H. New Clinical Applications of Electrolyzed Water: A Review. Microorganisms 2021, 9, 136. https://doi.org/10.3390/microorganisms9010136

AMA Style

Yan P, Daliri EB-M, Oh D-H. New Clinical Applications of Electrolyzed Water: A Review. Microorganisms. 2021; 9(1):136. https://doi.org/10.3390/microorganisms9010136

Chicago/Turabian Style

Yan, Pianpian, Eric Banan-Mwine Daliri, and Deog-Hwan Oh. 2021. "New Clinical Applications of Electrolyzed Water: A Review" Microorganisms 9, no. 1: 136. https://doi.org/10.3390/microorganisms9010136

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop