Hypochlorous Acid (HOCl) in Commercial Swine Production

Highlights of this CleanSmart White Paper

This White Paper reviews the current scientific evidence examining the use of hypochlorous acid (HOCl) in commercial swine production, including practical applications, operational considerations, and future research opportunities, while providing an objective assessment of its potential role within integrated swine biosecurity programs.

• Reviews the current scientific evidence supporting hypochlorous acid (HOCl) in commercial swine production.
• Examines the role of HOCl in barn sanitation, drinking-water quality, waterline sanitation, environmental hygiene, and integrated swine biosecurity.
• Summarizes current research involving important swine pathogens, including PRRSV, PEDV, African Swine Fever Virus (ASFV), Pseudorabies Virus, Salmonella, and Escherichia coli.
• Explains where current evidence supports practical implementation while identifying important operational limitations.
• Identifies research gaps and priorities for future commercial field validation.

This White Paper is part of the CleanSmart Resource Library, which provides evidence-based educational resources and technical publications on hypochlorous acid, cleaning, disinfection, and infection prevention.

Download a PDF copy of this White Paper to save for future reference, share with colleagues, or include as part of your commercial swine biosecurity, sanitation, and technical reference library.

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1.        Executive Summary

Hypochlorous acid (HOCl) is receiving increasing attention within the swine industry as researchers, veterinarians, and producers evaluate new approaches to biosecurity, sanitation, water quality management, and disease prevention. Current swine literature supports the antimicrobial activity of HOCl and slightly acidic electrolyzed water (SAEW) across a range of applications, including barn sanitation, drinking-water systems, environmental sanitation, and selected viral inactivation studies. The purpose of evaluating HOCl is not to determine whether it possesses antimicrobial activity. Numerous studies have already demonstrated activity against a variety of bacteria, viruses, fungi, and biofilms. The more important question for swine researchers is where HOCl may provide meaningful operational value within modern commercial swine production systems.

Several factors are driving interest in HOCl. Commercial swine operations face continual pressure to strengthen biosecurity while managing disease transmission, environmental hygiene, worker safety, water quality, antimicrobial stewardship, and operational efficiency. Unlike sanitation chemistries that are typically evaluated for a single application, HOCl has been investigated across multiple areas of swine production, including cleaned barn surfaces, drinking-water systems, selected air-sanitation applications, and routine equipment sanitation. At the same time, important limitations must be recognized. Swine facilities contain manure, feces, feed residue, bedding material, dust, biofilms, and other sources of organic contamination that can significantly reduce disinfectant performance. Current evidence consistently indicates that HOCl performs best when incorporated into broader sanitation programs that emphasize thorough cleaning, organic matter removal, appropriate contact time, and established biosecurity practices.

The strongest swine-specific evidence currently exists for barn sanitation, cleaned environmental surfaces, laboratory inactivation of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) and Pseudorabies Virus, and selected drinking-water applications in piglets. Emerging evidence also supports continued investigation of waterline sanitation, routine environmental hygiene, and integrated biosecurity programs. However, additional commercial-scale field validation remains warranted, particularly for manure systems, transport sanitation, air sanitation, waterline biofilms, and long-term economic performance under commercial production conditions. For swine researchers, the central question is not whether HOCl works under laboratory conditions. The central question is where HOCl can provide practical, economic, and operational value within commercial swine production systems.

1.1 Purpose of This Document

The purpose of this document is not to determine whether hypochlorous acid possesses antimicrobial activity. That question has largely been addressed within the scientific literature. Rather, the purpose of this document is to evaluate where HOCl may provide practical value within commercial swine production systems, summarize the current state of swine-related research, identify known limitations, and highlight areas where additional commercial field validation may be warranted.

Swine researchers and commercial producers face challenges that extend well beyond laboratory efficacy, including manure, organic load, dust, bedding materials, biofilms, water quality, transport biosecurity, worker safety, and ongoing disease pressure. Consequently, the most important question is not simply whether HOCl works, but how it fits within existing swine sanitation and biosecurity programs. Throughout this document, HOCl should be viewed as a potential component of a broader cleaning, sanitation, and biosecurity strategy rather than as a replacement for physical cleaning, manure removal, established disease-control practices, or comprehensive farm biosecurity programs.

Readers who are new to hypochlorous acid may find it helpful to first read What Is Hypochlorous Acid? Uses, Safety, and Cleaning in Canada, which explains what HOCl is, how it works, its antimicrobial properties, safety profile, and why it has become an important disinfectant technology across a wide range of commercial, institutional, and agricultural applications.

2.        Swine Production Context

Modern commercial swine production systems operate under continuous pressure to maintain herd health, support production efficiency, and minimize the risk of disease transmission. Effective sanitation and biosecurity programs are therefore fundamental components of successful swine operations. Unlike many industrial environments, swine facilities contain substantial organic matter. Manure, feces, feed residue, bedding materials, dust, moisture, and biofilms create conditions that support microbial survival while simultaneously reducing disinfectant performance. Water quality also represents an important consideration because drinking-water systems and waterlines can become reservoirs for microbial contamination and biofilm development if not properly managed. Consequently, environmental sanitation and water hygiene have become integral components of modern swine biosecurity programs.

Disease prevention remains a major industry priority. Porcine Reproductive and Respiratory Syndrome Virus (PRRSV), Porcine Epidemic Diarrhea Virus (PEDV), Salmonella, pathogenic Escherichia coli, Pseudorabies Virus, and numerous other bacterial and viral pathogens continue to drive investment in improved sanitation technologies and biosecurity practices. Interest in HOCl should be viewed within this broader context. Researchers are not evaluating HOCl because effective disinfectants do not already exist. Rather, they are evaluating whether HOCl may provide practical advantages within specific applications such as cleaned barn surfaces, drinking-water sanitation, environmental hygiene, selected biosecurity procedures, and integrated sanitation programs that complement existing disease-prevention strategies.

3.        Swine Applications of HOCl

Current swine literature has evaluated hypochlorous acid (HOCl) across a variety of production environments and operational objectives. Although implementation methods vary, the underlying goal is generally to reduce microbial contamination and support broader sanitation and biosecurity programs.

The diversity of applications is one reason swine researchers have become interested in HOCl. Rather than being investigated for only a single use, the literature suggests potential applicability across multiple areas of commercial swine production.

However, the existence of multiple applications should not be interpreted as evidence that a single implementation approach is appropriate for every situation. Delivery methods, concentrations, operational objectives, and production conditions all influence outcomes. Consequently, application-specific evaluation remains essential.

4.        HOCl Application Guidance for Swine Operations

It is important to recognize that HOCl is not intended to replace cleaning activities. Cleaning and disinfection serve different purposes within commercial swine production systems. Cleaning is primarily concerned with removing manure, feces, feed residue, bedding materials, dust, biofilms, and other sources of organic contamination, while disinfection is primarily concerned with reducing microbial contamination after cleaning has occurred. This distinction is particularly important because heavy organic load can significantly reduce disinfectant performance and limit the effectiveness of chlorine-based sanitizers.

As a result, HOCl should be viewed as a sanitation and biosecurity tool rather than as a substitute for cleaning, manure removal, facility maintenance, or other routine husbandry practices. For most swine operations, the practical question is not whether HOCl can replace existing sanitation programs, but whether it can provide additional value within those programs through improved environmental sanitation, drinking-water management, waterline hygiene, equipment sanitation, and broader biosecurity initiatives. The sections that follow review the current scientific evidence supporting these applications, identify important limitations and knowledge gaps, and highlight opportunities for future commercial field validation within modern swine production systems.

5.        Evidence Overview

The scientific literature surrounding hypochlorous acid (HOCl) and slightly acidic electrolyzed water (SAEW) within commercial swine production has expanded steadily over the past decade. Research has evaluated these technologies across a variety of swine applications, including barn sanitation, drinking-water management, waterline sanitation, environmental hygiene, viral inactivation, equipment sanitation, and broader biosecurity programs. While individual studies vary in design, available chlorine concentration, delivery method, contact time, and operating conditions, several recurring themes emerge from the literature.

First, antimicrobial activity has been demonstrated against a range of swine-relevant microorganisms under laboratory and controlled field conditions. Second, the effectiveness of any sanitation program remains heavily influenced by operational factors, including organic load, manure, biofilm formation, water quality, and application method. Third, some applications have accumulated considerably stronger evidence than others. Barn sanitation, laboratory viral inactivation studies, and selected drinking-water applications are supported by an increasing body of swine-specific research, while waterline biofilms, manure systems, transport sanitation, air sanitation under commercial conditions, and large-scale field validation remain considerably less developed.

The following sections summarize the current scientific evidence supporting each major application area, identify both the strengths and limitations of the available research, and highlight where additional commercial validation may further clarify the role of HOCl within integrated swine sanitation and biosecurity programs.

5.1 Barn Environmental Sanitation and Biosecurity

Barn environmental sanitation and biosecurity represent some of the most extensively investigated applications of hypochlorous acid (HOCl) within swine production. Researchers have evaluated sprayed, foamed, fogged, and atomized HOCl solutions for reducing microbial contamination on environmental surfaces throughout swine facilities, including pens, flooring, walls, feeders, drinkers, handling equipment, and transport vehicles. Particular attention has focused on pathogens of significance to swine production, including African swine fever virus (ASFV), porcine epidemic diarrhea virus (PEDV), porcine reproductive and respiratory syndrome virus (PRRSV), Salmonella, and Escherichia coli. Laboratory studies have demonstrated broad antimicrobial and virucidal activity under controlled conditions, supporting continued interest in HOCl as a component of swine biosecurity programs.

Environmental sanitation research has also extended beyond laboratory testing into commercial and simulated swine environments where contaminated surfaces, equipment, and shared production areas present ongoing opportunities for pathogen transmission. Many studies report reductions in microbial contamination following treatment, particularly when HOCl is applied after thorough cleaning and organic matter removal. These findings support continued evaluation of HOCl as an environmental sanitation tool within structured cleaning and biosecurity programs.

As with other sanitation technologies, commercial performance depends upon factors such as concentration, application method, contact time, and the presence of organic contamination. Current evidence therefore supports evaluating HOCl as one component of an integrated sanitation and biosecurity strategy while recognizing the need for continued commercial-scale field validation under typical swine production conditions.

5.2  Drinking Water Quality and Water Systems

Drinking-water quality represents one of the more promising applications of hypochlorous acid (HOCl) within commercial swine production. Researchers have investigated HOCl and slightly acidic electrolyzed water (SAEW) as tools for improving water hygiene, reducing microbial contamination within drinking-water systems, and limiting bacterial growth before water reaches the animals. Because drinking water is consumed continuously throughout all stages of production, maintaining microbiological quality is recognized as an important component of overall herd health and biosecurity. Consequently, interest has grown in evaluating whether HOCl can complement existing water management programs while supporting routine sanitation practices.

Several swine studies have reported reductions in bacterial contamination following treatment of drinking-water systems with HOCl or related electrolyzed water technologies. Research involving nursery pigs has also suggested potential improvements in water quality and reductions in microbial exposure during early production stages, where young animals are particularly susceptible to enteric disease challenges. Although the number of published field studies remains relatively limited compared with environmental sanitation research, the available evidence indicates that drinking-water applications warrant continued investigation because they combine routine implementation with the potential to improve overall water hygiene throughout commercial production systems.

As with all sanitation technologies, successful implementation depends upon operational conditions. Incoming water quality, organic contamination, biofilm development, system design, dosing practices, and routine maintenance all influence treatment effectiveness. Current evidence therefore supports viewing HOCl as one component of a comprehensive water management strategy rather than as a replacement for established water-quality monitoring, system maintenance, or biosecurity procedures. Additional commercial field studies will help determine the long-term operational, economic, and herd-health benefits of incorporating HOCl into routine drinking-water management programs within modern swine production.

5.3  Waterline Biofilms and Persistent Pathogens

Waterline sanitation is closely linked to drinking-water quality and represents an important area of interest for commercial swine operations evaluating hypochlorous acid (HOCl). Water distribution systems can support the development of biofilms, which are communities of microorganisms that attach to surfaces and become protected by a self-produced matrix. Once established, biofilms can serve as reservoirs for microbial contamination and reduce the effectiveness of routine sanitation efforts.

Although relatively few studies have evaluated commercial swine waterlines directly, research from swine and broader livestock production systems suggests that HOCl and related electrolyzed water technologies may support waterline hygiene when incorporated into routine maintenance programs. Continuous or intermittent treatment strategies have been proposed to help maintain cleaner distribution systems while supporting overall drinking-water quality. The available evidence is biologically plausible given HOCl's broad-spectrum antimicrobial activity, although it remains less extensive than that supporting environmental surface sanitation.

Biofilm management remains a complex issue, and no single sanitation technology should be viewed as a complete solution. Water chemistry, system design, flow characteristics, mineral deposition, organic contamination, and routine maintenance all influence outcomes. Nevertheless, the current literature suggests that waterline sanitation remains an important area for future commercial field evaluation to better define where HOCl can provide practical value within commercial swine production systems.

5.4  Viral Biosecurity and Disease Prevention

Disease prevention remains one of the primary drivers behind research into hypochlorous acid (HOCl) within commercial swine production. Laboratory studies have evaluated the virucidal activity of HOCl and slightly acidic electrolyzed water (SAEW) against economically significant swine pathogens, particularly Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) and Pseudorabies Virus. More recent investigations have also examined HOCl within broader biosecurity strategies intended to reduce the risk of transmission of high-consequence diseases such as African Swine Fever Virus (ASFV) and Porcine Epidemic Diarrhea Virus (PEDV). Collectively, these findings have contributed to growing interest in HOCl as a component of integrated swine biosecurity programs.

Much of the available evidence has been generated under controlled laboratory conditions using standardized concentrations, contact times, and environmental parameters. These studies generally demonstrate rapid viral inactivation under appropriate conditions and support continued evaluation of HOCl for disinfecting environmental surfaces, equipment, transport vehicles, and other potential fomites associated with indirect disease transmission.

As with other sanitation technologies, laboratory efficacy should not be equated with commercial performance. Organic contamination, application method, contact time, and operational conditions all influence outcomes. Consequently, current evidence supports evaluating HOCl as one component of a broader disease-prevention and biosecurity strategy while recognizing the need for continued commercial-scale field validation under typical swine production conditions.

5.5  Livestock Safety and Operational Compatibility

Safety and operational compatibility are important considerations when evaluating any sanitation technology used within commercial swine production. Livestock-focused technical evaluations and the available literature identify hypochlorous acid (HOCl) as a sanitation technology with potential applications across multiple agricultural environments, including swine facilities. When properly generated and used as directed, HOCl has attracted interest because of its broad-spectrum antimicrobial activity, favourable material compatibility, and comparatively low residue profile.

The available literature has identified no significant evidence that appropriately prepared HOCl presents undue risk to pigs when used for intended environmental sanitation applications. While outcomes remain dependent upon concentration, formulation, application method, and operating conditions, the current evidence supports continued evaluation of HOCl as one component of broader sanitation and biosecurity strategies rather than as a stand-alone solution.

5.6  Organic Load and Real-World Swine Environments

One of the most important considerations in swine sanitation is the presence of organic matter. Commercial swine facilities contain manure, slurry, feces, bedding materials, feed residue, dust, moisture, and other contaminants that create a far more complex environment than those typically encountered in laboratory efficacy studies. These materials can interfere with sanitation programs by shielding microorganisms, consuming available disinfectant, and reducing direct contact between antimicrobial agents and their intended microbial targets. As a result, the effectiveness demonstrated under controlled laboratory conditions may not always translate directly to commercial swine operations.

The influence of organic load is not unique to hypochlorous acid. Most disinfectant technologies experience some reduction in performance when exposed to significant quantities of organic matter. For this reason, swine sanitation programs have traditionally emphasized thorough cleaning and organic matter removal before disinfection. Mechanical removal of manure, slurry, feed residue, bedding, dust, and other debris remains one of the most important steps in any sanitation protocol because it reduces the overall microbial burden while improving the ability of disinfectants to contact target organisms effectively.

Several swine studies directly reinforce the importance of this principle. Research evaluating slightly acidic electrolyzed water within swine barns reported substantially greater reductions in microbial contamination when surfaces were cleaned before disinfectant application, demonstrating that sanitation effectiveness depends upon both cleaning and disinfection rather than either activity alone. These findings are consistent with broader livestock sanitation research and support the view that HOCl performs best as part of a structured cleaning-and-disinfection sequence rather than as a substitute for cleaning itself.

From an operational perspective, swine producers should therefore view HOCl as a sanitation tool that complements existing cleaning and biosecurity programs. It is not intended to replace manure removal, washing procedures, routine facility maintenance, or other practices designed to reduce organic contamination. Instead, its potential value lies in improving microbial control after cleaning has been completed and in supporting ongoing environmental sanitation, water hygiene, equipment sanitation, and integrated biosecurity programs throughout commercial swine production.

5.7  Literature Gaps and Research Opportunities

The strongest evidence currently exists for barn environmental sanitation, laboratory viral inactivation, cleaned-surface disinfection, and selected drinking-water applications. Moderate evidence supports waterline sanitation, broader environmental hygiene, and integrated biosecurity programs, although outcomes remain influenced by organic load, application method, and commercial operating conditions. Important knowledge gaps remain regarding long-term waterline management, manure and slurry systems, air sanitation under commercial conditions, transport sanitation, economic performance, and large-scale comparative evaluations against established livestock disinfectants.

Many of the most important questions now facing swine researchers involve practical implementation rather than laboratory efficacy. Additional commercial field studies are needed to evaluate long-term operational value, return on investment, optimal application protocols, biofilm management, organic-load tolerance, and performance under realistic production conditions. These gaps should not be viewed as weaknesses of the technology itself. Rather, they represent opportunities for future research that will help determine where hypochlorous acid can provide the greatest practical, economic, and biosecurity benefits within modern commercial swine production systems.

6.        Research Reference Library

The research discussed throughout this report is derived from a diverse body of swine, veterinary, agricultural, sanitation, biosecurity, and water-management literature. Rather than presenting detailed study summaries within the main body of the report, supporting references have been consolidated into the appendices to improve readability while maintaining focus on practical and operational considerations.

Appendix B provides a reference library summarizing the principal studies reviewed during preparation of this report, including application area, country of origin, key findings, and practical relevance. Appendix C provides a focused summary of literature related to organic load, biofilms, environmental contamination, water quality, and other operational factors that may influence sanitation performance under commercial swine production conditions.

Readers seeking additional information regarding specific studies, methodologies, or application areas are encouraged to consult the appendices alongside the relevant sections of this report.

7.        Operational Considerations

7.0 The Role of HOCl Within a Swine Sanitation Program

Before evaluating the potential advantages or limitations of hypochlorous acid (HOCl), it is important to understand the role it is intended to play within a swine production system. Modern swine operations rely on multiple, complementary sanitation practices designed to support herd health, reduce disease transmission, and maintain production efficiency. Cleaning, disinfection, water management, biosecurity, ventilation, monitoring, and routine facility maintenance each contribute to the overall effectiveness of a herd-health program.

Cleaning and disinfection are closely related but serve different purposes. Cleaning focuses on the removal of manure, slurry, bedding residue, feed waste, dust, and other forms of organic contamination from barns, pens, farrowing facilities, transport equipment, and water systems. This process reduces the overall microbial burden while improving the ability of disinfectants to contact target microorganisms. Disinfection follows cleaning and is intended to reduce microbial contamination on properly prepared surfaces. Because organic matter can significantly reduce disinfectant performance, thorough cleaning remains one of the most important components of any swine sanitation program.

Within this framework, HOCl should be viewed as a sanitation and biosecurity tool rather than as a replacement for cleaning. Potential applications identified within the current literature include environmental sanitation, drinking-water management, waterline sanitation, equipment sanitation, transport vehicle sanitation, and broader biosecurity programs. The objective is not to replace established sanitation protocols, but to evaluate whether HOCl can strengthen specific components of those programs by supporting microbial control where it is most operationally beneficial.

This distinction is particularly important because many of the sanitation challenges facing swine operations originate from factors that cannot be addressed by disinfection alone. Manure accumulation, slurry handling, biofilm development within water systems, equipment design, ventilation, stocking density, and day-to-day management practices all influence microbial pressure and disease risk. Consequently, the effectiveness of any sanitation technology depends not only on its antimicrobial properties but also on how successfully it can be integrated into an overall herd-health and biosecurity strategy.

7.1 Why Swine Operations Are Evaluating HOCl

The swine industry has long relied on a variety of sanitation technologies, and interest in hypochlorous acid (HOCl) is not driven by a lack of existing disinfectants. Rather, researchers and commercial producers are evaluating whether HOCl may provide practical value within specific applications or operational environments. Particular interest has emerged in barn sanitation, drinking-water management, waterline sanitation, environmental hygiene, transport sanitation, and broader biosecurity programs.

HOCl has been investigated across multiple swine applications, creating the potential for a single sanitation chemistry to support several operational objectives. Researchers have also examined viral inactivation, water quality management, equipment compatibility, worker handling characteristics, and implementation flexibility. While outcomes remain dependent upon operational conditions, the available literature suggests that several of these applications warrant continued evaluation and commercial field validation.

7.2 Implementation Considerations

The effectiveness of any sanitation technology depends upon how it is implemented. While laboratory studies evaluate disinfectants under controlled conditions, commercial swine operations introduce variables such as organic load, water quality, application method, contact time, facility design, animal movement, and operational consistency that can influence performance. Swine studies have evaluated hypochlorous acid (HOCl) across a range of concentrations and delivery methods, including environmental spraying, drinking-water treatment, waterline sanitation, equipment sanitation, and transport biosecurity applications. Consequently, successful implementation requires application-specific protocols supported by monitoring and verification activities such as environmental sampling, water-quality testing, microbial monitoring, and routine biosecurity assessment.

7.3 Organic Matter Management Strategy

Organic matter management remains one of the most important factors influencing sanitation performance within commercial swine production. Unlike controlled laboratory environments, swine facilities contain continual accumulations of manure, slurry, bedding materials, feed residue, dust, moisture, and biofilms. These materials can increase microbial burden while also reducing disinfectant performance by limiting direct contact between antimicrobial agents and target microorganisms. For this reason, effective sanitation begins with thorough physical cleaning before disinfection.

A practical swine sanitation sequence typically begins with the removal of manure and bedding, followed by dry cleaning, washing, and the elimination of remaining organic contamination. Once these steps have been completed, disinfectants can be applied more effectively because microbial targets are more accessible and less protected by organic material. Monitoring activities such as visual inspection, environmental sampling, water-quality testing, or microbial assessment may then be used to evaluate sanitation effectiveness before animals are reintroduced.

Within this framework, HOCl should be viewed as a tool that supports the disinfection and maintenance phases of a sanitation program rather than the cleaning phase. It is not intended to replace manure removal, washing procedures, or other activities designed to reduce organic contamination. Instead, its potential value lies in supporting microbial control after cleaning has occurred and as part of ongoing sanitation and biosecurity programs.

7.4 The Challenge of Persistent Pathogens

Persistent microbial contamination remains a challenge within commercial swine production despite routine cleaning and disinfection efforts. Biofilms, organic load, facility design, waterline contamination, equipment surfaces, and environmental conditions can all contribute to recurring microbial presence. For this reason, researchers continue to evaluate sanitation technologies, including hypochlorous acid (HOCl), as part of broader efforts to improve microbial control within commercial swine operations.

No single sanitation technology is capable of eliminating every source of microbial persistence. Effective pathogen control depends on integrating appropriate cleaning procedures, biosecurity practices, water-quality management, environmental sanitation, and routine monitoring. Within this broader framework, HOCl should be viewed as one potential component of a comprehensive sanitation strategy rather than as a stand-alone solution.

7.5 Potential Advantages and Potential Limitations of HOCl

A balanced assessment of hypochlorous acid (HOCl) requires consideration of both its potential advantages and its potential limitations. The available swine literature suggests several areas where HOCl may provide value within commercial production systems while also identifying important factors that can influence performance. The following table summarizes the principal advantages and limitations identified throughout the current swine literature.

No sanitation technology is without limitations, and HOCl is no exception. The available swine literature suggests that HOCl offers several potential advantages across commercial production systems while also recognizing that performance depends upon appropriate implementation and operating conditions. As with other sanitation technologies, HOCl is best viewed as one component of a broader cleaning, sanitation, and biosecurity program rather than as a stand-alone solution.

8.        Questions for Industry Evaluation

The growing body of swine-related HOCl research provides evidence that the technology warrants continued evaluation. However, the most important questions facing researchers, veterinarians, and commercial producers are no longer limited to antimicrobial activity alone. Practical implementation, operational value, economic considerations, and long-term performance under commercial production conditions are increasingly important areas of investigation.

The purpose of this chapter is not to advocate for a particular sanitation approach. Rather, it is to identify the key questions that researchers, veterinarians, biosecurity specialists, and commercial swine producers may wish to consider when evaluating HOCl within modern swine production systems.

8.1 Key Evaluation Considerations

When evaluating HOCl within commercial swine production systems, researchers should focus on practical outcomes rather than antimicrobial activity alone. Important considerations include barn sanitation, drinking-water management, waterline sanitation, environmental hygiene, viral biosecurity, operational practicality, and integration within existing sanitation and biosecurity programs. Because swine operations differ in facility design, production stage, water quality, disease pressure, and management practices, application-specific evaluation is often more valuable than broad generalizations regarding performance.

Researchers may also wish to consider implementation factors such as monitoring requirements, equipment compatibility, labor demands, maintenance considerations, and overall program consistency. Ultimately, the most meaningful evaluations are likely to be those that examine how HOCl performs within complete swine-management systems rather than as an isolated sanitation intervention.

8.2 What We Know and What We Still Need to Learn

Current swine research supports the antimicrobial activity of HOCl across a range of applications, including barn sanitation, environmental hygiene, selected drinking-water systems, waterline management, and laboratory viral inactivation studies. These findings provide a foundation for continued investigation while also demonstrating that research maturity varies across individual applications.

At the same time, important questions remain. Additional commercial-scale field studies are needed to evaluate long-term performance under typical production conditions, including environments characterized by heavy organic load, variable water quality, diverse facility designs, and ongoing disease pressure. Future research may also help clarify where HOCl provides the greatest practical, operational, and economic value within integrated swine sanitation and biosecurity programs.

8.3 Industry Adoption and Future Evaluation

Current evidence suggests that hypochlorous acid has potential applications across multiple aspects of swine production, including barn sanitation, water quality management, waterline sanitation, biosecurity, and selected disease-control programs. However, the relative value of each application will ultimately depend on the specific operational objectives, facility design, management practices, and economic considerations of individual swine operations.

As additional commercial experience and field research become available, the greatest opportunities may lie in identifying where HOCl provides the strongest combination of practical implementation, measurable operational benefit, and compatibility with existing sanitation and biosecurity programs. Continued evaluation under commercial production conditions will help clarify where HOCl can provide the greatest value within modern swine production systems.

9.        Frequently Asked Research Questions

9.1 What is hypochlorous acid (HOCl)?

Answer

Hypochlorous acid (HOCl) is an antimicrobial compound that has been investigated for sanitation, biosecurity, and water-quality applications in livestock production. Within swine production, the current literature focuses on where HOCl may provide practical operational value rather than whether it possesses antimicrobial activity.

Primary References

Hypochlorous Acid: A Review

View Publication

9.2 Why is HOCl being evaluated for commercial swine production?

Answer

Researchers are investigating HOCl for applications including barn sanitation, drinking-water systems, waterline sanitation, environmental hygiene, and biosecurity. The strongest evidence currently supports barn surface sanitation, selected drinking-water applications, and laboratory viral inactivation studies.

Primary References

Disinfection effectiveness of slightly acidic electrolysed water in swine barns

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Effect of Slightly Acidic Electrolyzed Water on Growth, Diarrhea and Intestinal Bacteria of Newly Weaned Piglets

View Publication

9.3 Can HOCl replace routine cleaning procedures?

Answer

No. The available literature consistently indicates that HOCl should be used as part of a cleaning-then-disinfection workflow. Organic matter can reduce antimicrobial performance, making physical cleaning an essential first step before disinfection.

Primary References

Disinfection effectiveness of slightly acidic electrolysed water in swine barns

View Publication

Electrolyzed water as a disinfectant: A systematic review of factors affecting the production and efficiency of hypochlorous acid

View Publication

9.4 Can HOCl be used for drinking-water and waterline applications?

Answer

The evidence for drinking-water applications is encouraging, particularly in newly weaned piglets, where reductions in water bacteria, coliforms, and diarrhea were reported. Evidence supporting waterline sanitation is more limited, and additional commercial field validation is still needed.

Primary References

Effect of Slightly Acidic Electrolyzed Water on Growth, Diarrhea and Intestinal Bacteria of Newly Weaned Piglets

View Publication

9.5 Is HOCl effective against swine viruses?

Answer

Laboratory studies have demonstrated virucidal activity against Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) and Pseudorabies Virus. However, the available evidence is primarily laboratory-based, and additional commercial field studies are needed to determine performance under routine production conditions.

Primary References

In vitro inactivation of porcine reproductive and respiratory syndrome virus and pseudorabies virus by slightly acidic electrolyzed water

View Publication

9.6 Is HOCl safe to use around pigs?

Answer

The available studies identified in this review report no obvious adverse effects under the reported conditions, including drinking-water studies involving piglets and fattening pigs. The report also notes that additional research is needed to validate safety across broader production stages and operating conditions.

Primary References

Effect of Slightly Acidic Electrolyzed Water on Growth, Diarrhea and Intestinal Bacteria of Newly Weaned Piglets

View Publication

Effects of drinking slightly acidic electrolyzed water on the growth performance and health of fattening pigs

View Publication

9.7. What is the biggest limitation affecting HOCl performance?

Answer

The current literature consistently identifies organic matter as one of the most important factors influencing performance. Manure, feces, feed particles, dust, and other organic materials can reduce antimicrobial activity, reinforcing the importance of thorough cleaning before disinfection.

Primary References

Disinfection effectiveness of slightly acidic electrolysed water in swine barns

View Publication

Electrolyzed water as a disinfectant: A systematic review of factors affecting the production and efficiency of hypochlorous acid

View Publication

9.8 What additional research is still needed?

Answer

The approved research identifies several priorities for future investigation, including commercial nursery and farrow-to-finish field trials, waterline biofilm studies, transport sanitation trials, comparative disinfectant studies, and commercial economic evaluations.

Primary References

No specific publication was identified for this summary because it reflects the overall conclusions and research priorities presented in the approved Perplexity review.

Appendix A – Glossary of Terms

Antimicrobial Activity

The ability of a substance to reduce or inactivate microorganisms, including bacteria, viruses, fungi, and other microbes.

Available Chlorine Concentration (ACC)

The concentration of chlorine-based antimicrobial compounds available to provide disinfection, commonly used to characterize electrolyzed water solutions.

Biofilm

A community of microorganisms attached to a surface and protected by a self-produced matrix, making the microorganisms more difficult to remove or inactivate.

Biosecurity

A combination of management practices intended to reduce the introduction, spread, and persistence of infectious diseases within livestock production systems.

Commercial Field Validation

Evaluation of a technology under normal commercial production conditions rather than under controlled laboratory conditions.

Contact Time

The period during which a disinfectant remains in contact with a surface or microorganism to achieve its intended antimicrobial effect.

Disinfection

The process of reducing or inactivating microorganisms on surfaces or equipment after cleaning has removed visible contamination.

Electrolyzed Water (EW)

Water produced through electrolysis that generates antimicrobial chlorine species. Depending on production conditions, it may be acidic, neutral, or slightly acidic.

Environmental Sanitation

The cleaning and disinfection of buildings, equipment, and environmental surfaces to reduce microbial contamination.

Hypochlorous Acid (HOCl)

A weak acid and naturally occurring antimicrobial molecule that can also be generated commercially for sanitation, water treatment, and biosecurity applications.

Organic Load

Organic materials such as manure, feces, bedding, feed residue, dust, and other debris that can reduce disinfectant performance if not removed before disinfection.

Pathogen

A microorganism capable of causing disease, including certain bacteria, viruses, fungi, or parasites.

Porcine Reproductive and Respiratory Syndrome Virus (PRRSV)

An economically important swine virus that has been evaluated in laboratory studies investigating the virucidal activity of slightly acidic electrolyzed water.

Pseudorabies Virus (PRV)

A swine herpesvirus included in laboratory studies evaluating the antiviral activity of slightly acidic electrolyzed water.

Sanitation

The combined process of cleaning and disinfection used to reduce microbial contamination within production environments.

Slightly Acidic Electrolyzed Water (SAEW)

A form of electrolyzed water produced within a mildly acidic pH range that contains hypochlorous acid as the predominant antimicrobial species.

Waterline Sanitation

The cleaning and maintenance of livestock drinking-water distribution systems to help reduce microbial contamination and biofilm development.

Appendix B – Poultry HOCl Research Catalogue

1. General HOCl Science and Reviews

1.1 Antimicrobial Efficacy, Mode of Action and In Vivo Use of Hypochlorous Acid (HOCl) for Prevention or Therapeutic Support of Infections

View Publication

Comprehensive review of the antimicrobial mechanisms, clinical applications, and therapeutic potential of hypochlorous acid.

1.2 Electrolyzed Water as a Disinfectant: A Systematic Review of Factors Affecting the Production and Efficiency of Hypochlorous Acid

View Publication

Systematic review examining the factors that influence the production, stability, and antimicrobial effectiveness of electrolyzed water.

1.3 Hypochlorous Acid: A Review

View Publication

Overview of the chemistry, antimicrobial activity, safety, and practical applications of hypochlorous acid.

2. Swine Production Applications

2.1 Applications, Usage Levels, and Benefits of Hypochlorous Acid in Pig Farming

View Publication

Review of potential applications of hypochlorous acid within commercial swine production, including sanitation and water management.

2.2 Disinfection Effectiveness of Slightly Acidic Electrolyzed Water in Swine Barns

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Evaluated the effectiveness of slightly acidic electrolyzed water for reducing microbial contamination within commercial swine barns.

2.3 Effect of Slightly Acidic Electrolyzed Water on Growth, Diarrhea and Intestinal Bacteria of Newly Weaned Piglets

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Investigated the effects of slightly acidic electrolyzed water on growth performance, diarrhea incidence, and intestinal bacteria in newly weaned piglets.

3. Viral Disease Control

3.1 Effects of Disinfection on the Molecular Detection of Porcine Epidemic Diarrhea Virus

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Evaluated how disinfection influences the molecular detection of porcine epidemic diarrhea virus (PEDV) following environmental decontamination.

3.2 Evaluation of Sprayed Hypochlorous Acid Solutions for Their Virucidal Ability

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Evaluated the virucidal activity of sprayed hypochlorous acid solutions against multiple viruses under controlled laboratory conditions.

3.3 In Vitro Inactivation of Porcine Reproductive and Respiratory Syndrome Virus and Pseudorabies Virus by Slightly Acidic Electrolyzed Water

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Investigated the effectiveness of slightly acidic electrolyzed water against PRRSV and Pseudorabies virus under laboratory conditions.

3.4 Virucidal Effects of Hypochlorous Acid Water on Porcine Epidemic Diarrhea Virus

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Investigated the virucidal activity of hypochlorous acid water against porcine epidemic diarrhea virus (PEDV).

4. Livestock Biosecurity

4.1 Hypochlorous Acid in Cattle Production: A Review of Applications, Efficacy, and Future Prospects in Sub-Saharan Africa

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Narrative review summarizing current evidence on hypochlorous acid (HOCl) applications in cattle production, including biosecurity, environmental sanitation, drinking-water hygiene, wound management, and future research priorities for livestock systems.

5. Regulatory and Government References

5.1 Chlorine Materials

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USDA National Organic Program information describing approved chlorine materials for organic production systems.

5.2 Cleaners, Disinfectants and Sanitizers – Organic Federation of Canada

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Guidance describing the use of cleaners, disinfectants, and sanitizers within Canadian organic production systems.

5.3 Commission Implementing Regulation (EU) 2021/347 of 25 February 2021

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European Commission regulation approving active chlorine released from hypochlorous acid for specified biocidal product types.

5.4 Commission Implementing Regulation (EU) 2021/365

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European Commission regulation concerning the approval of active chlorine generated from hypochlorous acid for biocidal applications.

5.5 Formal Recommendation

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USDA National Organic Standards Board formal recommendation regarding hypochlorous acid for livestock applications.

5.6 Hypochlorous Acid – Agricultural Marketing Service

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USDA technical evaluation report reviewing hypochlorous acid for use within livestock production systems.

5.7 Hypochlorous Acid Livestock – Agricultural Marketing Service

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USDA technical report providing additional evaluation of hypochlorous acid for livestock applications.

5.8 Product Information – Canada.ca

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Health Canada Drug Product Database entry for a hypochlorous acid product authorized in Canada

Appendix C – Why Evaluate HOCl Alongside Existing Swine Sanitation Technologies?

Commercial swine operations already utilize a variety of sanitation technologies, including quaternary ammonium compounds (quats), chlorine-based disinfectants, hydrogen peroxide products, peroxygen chemistries, iodophors, and other antimicrobial agents. The purpose of evaluating HOCl is not to suggest that these technologies are ineffective. Rather, the objective is to determine whether HOCl may provide additional value within specific swine applications and operational environments.

Researchers have shown particular interest in HOCl because it has been investigated across multiple swine applications, including barn sanitation, drinking-water management, waterline sanitation, environmental sanitation, viral biosecurity, and broader herd-health programs. Few sanitation technologies have been studied across such a wide range of swine-related applications. This versatility has contributed to growing industry interest, particularly in areas where water quality management, biofilm control, and environmental hygiene remain ongoing operational challenges.

Another factor driving interest is the growing body of literature supporting drinking-water applications and environmental sanitation. Water quality can influence microbial contamination, biofilm development, and overall herd-management practices. Because HOCl has been investigated in these areas, researchers are increasingly interested in understanding whether improvements in water hygiene and environmental sanitation may contribute to broader operational benefits.

Like all disinfectants, however, HOCl has limitations. Organic matter can reduce effectiveness, cleaning remains essential, and performance depends upon concentration, application method, water quality, environmental conditions, and overall program design. Current evidence does not support viewing HOCl as a replacement for manure removal, facility cleaning, washing procedures, or existing sanitation and biosecurity programs.

For swine researchers, veterinarians, and commercial producers, the key question is therefore not whether HOCl should replace existing sanitation technologies. The more relevant question is whether it can strengthen specific components of integrated sanitation and biosecurity programs while providing practical, operational, or economic advantages under commercial production conditions. Continued research and commercial field evaluation will help determine where HOCl can provide the greatest value within modern swine production systems.

Appendix D – Proposed Commercial Field Trial Measurements

The current swine literature provides encouraging evidence for several HOCl applications. However, many of the most important questions facing researchers and commercial producers involve performance under commercial production conditions rather than laboratory efficacy alone. The following framework identifies potential measurements that may be useful when evaluating HOCl within modern swine production systems.

Barn Environmental Sanitation Programs

Objective

Evaluate the effectiveness of HOCl for reducing microbial contamination within commercial swine housing environments.

Potential Measurements

• Surface microbial counts
• Environmental pathogen detection
• ATP monitoring
• Visual cleanliness assessments
• Cleaning and disinfection consistency
• Labour and application requirement

Drinking-Water Management Programs

Objective

Evaluate the influence of HOCl-treated drinking water on water hygiene and selected herd health indicators.

Potential Measurements

• Water microbial counts
• Water-quality parameters
• Water consumption
• Growth performance
• Diarrhea incidence
• General herd health observation
  

Waterline Sanitation Programs

Objective

Evaluate the impact of HOCl on waterline hygiene and biofilm management within commercial swine facilities.

Potential Measurements

• Biofilm observations
• Waterline microbial counts
• Water-quality indicators
• Waterline cleanliness
• Maintenance requirements
• Operational consistency

Viral Biosecurity Programs

Objective

Evaluate the contribution of HOCl to routine biosecurity programs intended to reduce environmental viral contamination.

Potential Measurements

• Environmental viral detection
• Surface sampling results
• Biosecurity protocol compliance
• Cleaning consistency
• Operational practicality
• Application frequency

Integrated Sanitation and Biosecurity Programs

Objective

Evaluate the overall contribution of HOCl when incorporated into existing commercial cleaning, sanitation, and biosecurity programs.

Potential Measurements

• Overall sanitation program consistency
• Equipment compatibility
• Water usage
• Labour requirements
• Operational costs
• Producer observations and implementation experience

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