Hypochlorous Acid (HOCl) in Poultry Production

Highlights of this CleanSmart White Paper

Hypochlorous acid (HOCl) is receiving increasing attention within the poultry industry as producers, veterinarians, and researchers seek practical approaches to improving biosecurity, sanitation, water quality, and disease prevention. This White Paper reviews the current scientific evidence examining the use of HOCl across a range of poultry applications and provides an objective assessment of the current state of the research.

• Current scientific evidence supports hypochlorous acid (HOCl) as a promising component of poultry biosecurity programs, particularly for drinking-water management, waterline sanitation, hatchery sanitation, egg sanitation, and environmental sanitation.
• The strongest research evidence currently supports HOCl applications involving drinking-water systems, waterline sanitation, hatchery sanitation, egg sanitation, and environmental biosecurity, while additional commercial-scale field validation remains warranted for some applications.
• Hypochlorous acid performs best when incorporated into comprehensive sanitation and biosecurity programs that include effective cleaning, organic matter removal, and routine biosecurity practices.
• Poultry production environments present operational challenges—including organic load, dust, litter, manure, biofilms, and water quality—that can influence disinfectant performance under commercial conditions.
• Current research suggests that hypochlorous acid may provide meaningful operational value across multiple poultry applications, although practical outcomes remain dependent on factors such as application method, concentration, contact time, and environmental conditions.

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 poultry biosecurity, sanitation, and technical resource library.

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1.        Executive Summary

Hypochlorous acid (HOCl) is receiving increasing attention within the poultry industry as researchers and producers evaluate new approaches to biosecurity, sanitation, water quality management, and disease prevention. Current poultry literature supports the antimicrobial activity of HOCl across a range of applications, including drinking-water systems, waterline sanitation, hatchery sanitation, egg sanitation, environmental sanitation, and poultry-house biosecurity. 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 poultry researchers is where HOCl may provide meaningful operational value within modern poultry production systems.

Several factors are driving interest in HOCl. Poultry operations face increasing pressure to maintain effective biosecurity programs while managing water quality, environmental sanitation, pathogen control, worker safety, and operational efficiency. Unlike some sanitation chemistries that are primarily used for a single purpose, HOCl has been investigated across multiple poultry applications, creating interest in its potential as a multi-application biosecurity tool. At the same time, important limitations must be recognized. Poultry environments contain manure, litter, dust, feathers, feed residue, biofilms, and other sources of organic contamination that can interfere with disinfectant performance. Current evidence suggests that HOCl performs best when incorporated into broader sanitation programs that include cleaning, organic matter removal, verification, and ongoing biosecurity practices.

The strongest poultry evidence currently exists in drinking-water management, waterline sanitation, hatchery sanitation, egg sanitation, and environmental biosecurity applications. Evidence also supports further investigation of air sanitation, poultry-house sanitation, and pathogen-control programs. However, additional commercial-scale field validation remains warranted, particularly in environments characterized by heavy organic load and complex operating conditions. For poultry 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 poultry 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 poultry production systems, summarize the current state of poultry-related research, identify known limitations, and highlight areas where additional field validation may be warranted.

Poultry researchers and commercial operators face challenges that extend beyond laboratory efficacy, including organic load, litter, manure, dust, biofilms, water quality, operational complexity, worker safety, and disease pressure. As a result, the most important question is not simply whether HOCl works, but how it fits within existing poultry 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 cleaning, litter management, manure removal, or established disease-control practices.

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, and why it has become an important disinfectant and cleaning technology across a wide range of applications.

2.        Poultry Production Context

Modern poultry production systems operate under continuous pressure to maintain flock health, support production performance, and minimize the risk of disease transmission. Effective sanitation and biosecurity programs are therefore critical components of commercial poultry operations. Unlike many industrial environments, poultry facilities contain substantial organic matter. Manure, litter, feed fines, dust, feathers, and moisture create conditions that can support microbial survival and biofilm formation while also creating challenges for sanitation programs because organic matter can interfere with disinfectant performance and make environmental control more difficult. Water quality represents another important consideration, as poultry drinking-water systems can serve as reservoirs for microbial growth and biofilm development if not properly managed. Consequently, waterline sanitation programs are an important component of many poultry biosecurity strategies.

Disease prevention remains a major industry concern. Avian influenza, Salmonella, E. coli, Newcastle disease, infectious bronchitis, and other pathogens continue to drive investment in sanitation and biosecurity technologies. As a result, poultry producers routinely evaluate new approaches that may strengthen existing disease-control programs. The interest in HOCl should be viewed within this broader context. Researchers are not evaluating HOCl because sanitation technologies do not already exist. Rather, they are evaluating whether HOCl may provide advantages in specific applications such as water quality management, waterline sanitation, environmental sanitation, hatchery operations, egg sanitation, or integrated biosecurity programs.

3.        Poultry Applications of HOCl

Current poultry literature has evaluated 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 biosecurity programs.

The diversity of applications is one reason poultry researchers have become interested in HOCl. Rather than being investigated for only a single use, the literature suggests potential applicability across multiple areas of poultry production.  However, the existence of multiple applications should not be interpreted as evidence that a single approach is appropriate for all situations. Delivery methods, concentrations, operational objectives, and environmental conditions all influence outcomes. Consequently, application-specific evaluation remains important.

4.        HOCl Application Guidance for Poultry Operations

It is important to recognize that HOCl is not intended to replace cleaning activities. Cleaning and disinfection serve different purposes within poultry production systems. Cleaning is primarily concerned with removing manure, litter, dust, feathers, feed residue, 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 interfere with disinfectant performance.

As a result, HOCl should be viewed as a sanitation and biosecurity tool rather than as a substitute for cleaning, litter management, manure removal, or other routine facility-maintenance activities. For most poultry 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 water quality management, waterline sanitation, environmental sanitation, hatchery sanitation, egg sanitation, or broader biosecurity initiatives. The sections that follow review the current research evidence supporting these applications, identify limitations and knowledge gaps, and outline opportunities for future field validation under commercial poultry conditions.

5.        Evidence Overview

The poultry literature surrounding hypochlorous acid has expanded significantly over the past two decades. Research has evaluated HOCl and related electrolyzed water technologies across a variety of poultry applications, including environmental sanitation, drinking-water management, waterline sanitation, hatchery sanitation, egg sanitation, pathogen control, and biosecurity programs. While individual studies vary in design, concentration, delivery method, and operating conditions, several recurring themes emerge from the literature.

First, antimicrobial activity has been demonstrated across a broad range of poultry-relevant microorganisms. Second, the effectiveness of any sanitation program remains heavily influenced by operational conditions, including organic load, biofilm formation, water quality, and application method. Third, some applications have accumulated considerably more evidence than others. Drinking-water management, waterline sanitation, egg sanitation, and hatchery sanitation are supported by a growing body of literature, while direct litter treatment, direct manure treatment, and large-scale commercial field validation remain less extensively studied.

The following sections summarize the current evidence base and identify both the strengths and limitations of the available research.

5.1 Air and Surface Biosecurity

Air and surface sanitation are among the most frequently discussed poultry applications for HOCl. Researchers have investigated the ability of sprayed, fogged, or atomized HOCl solutions to reduce microbial contamination on environmental surfaces and within poultry-house environments. Particular attention has been directed toward pathogens of significance to poultry production, including avian influenza virus, Newcastle disease virus, infectious bronchitis virus, Salmonella, and E. coli. Several studies from Japan have reported virucidal activity against avian influenza virus under controlled laboratory conditions, while additional research has reported activity against Newcastle disease virus and infectious bronchitis virus, contributing to growing interest in HOCl as a potential component of poultry biosecurity programs.

Environmental sanitation studies have extended beyond laboratory testing. Research involving poultry-house environments and poultry housing surfaces has evaluated the use of sprayed or fogged hypochlorous acid and slightly acidic electrolyzed water on floors, walls, feed troughs, cages, and water pipes. These studies generally report reductions in microbial contamination following treatment, supporting continued investigation of HOCl as an environmental sanitation tool. The evidence suggests that HOCl may have practical applications in poultry-house sanitation, although outcomes remain dependent upon concentration, application method, contact time, and environmental conditions.

An important distinction must be made between laboratory efficacy and commercial poultry-house performance. Poultry facilities contain dust, litter particles, feathers, feed fines, manure, moisture gradients, and other sources of organic contamination that can influence how disinfectants interact with microbial targets. The current evidence supports HOCl as a promising environmental sanitation and biosecurity tool while also demonstrating the importance of evaluating performance under realistic commercial conditions.

5.2  Drinking Water Quality

Drinking-water quality is one of the most extensively studied poultry applications for hypochlorous acid. Poultry drinking-water systems can serve as reservoirs for microbial growth, biofilm formation, and water-quality deterioration, making water management an important component of overall flock health and biosecurity programs. As a result, researchers have investigated whether low-concentration HOCl treatment can support cleaner drinking-water systems while maintaining normal production performance.

One of the most significant recent studies evaluated the long-term use of low-concentration HOCl in broiler drinking water throughout the production cycle. Researchers reported reductions in microbial load within cecal contents and fresh manure while maintaining overall growth performance. These findings are notable because they suggest that HOCl may influence microbial populations within poultry production systems without negatively affecting key production outcomes. Additional poultry literature has also identified potential benefits related to water quality management and waterline hygiene, further contributing to industry interest in drinking-water applications.

While the current evidence is encouraging, important questions remain regarding optimal concentrations, treatment protocols, water quality conditions, and long-term implementation strategies under commercial operating conditions. Nevertheless, drinking-water management represents one of the strongest evidence areas currently available within the poultry HOCl literature.

5.3  Waterline Biofilms and Persistent Pathogens

Waterline sanitation is closely linked to drinking-water quality and represents one of the most practical areas of interest for poultry operations evaluating HOCl. Poultry 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, contribute to declining water quality, and complicate sanitation efforts throughout the production cycle.

Several poultry studies and industry reviews have identified waterline management as a potential application for HOCl and related electrolyzed water technologies. Researchers have investigated continuous low-dose treatment strategies designed to support water hygiene and reduce microbial contamination within distribution systems. The literature consistently identifies biofilm control as an important objective within poultry water-management programs because biofilms can harbor persistent microorganisms, including Salmonella and E. coli, while reducing the effectiveness of routine sanitation efforts.

Biofilm management remains a complex issue, and no single sanitation technology should be viewed as a complete solution. Water quality, system design, maintenance practices, organic load, and treatment protocols all influence outcomes. Nevertheless, the available literature suggests that waterline sanitation represents one of the most promising areas for future field evaluation because improvements in water hygiene have the potential to influence multiple aspects of poultry production simultaneously.

5.4  Hatchery and Egg Sanitation

Hatcheries represent a critical control point within poultry production because microbial contamination at this stage can affect downstream flock health, biosecurity, and production performance. Hypochlorous acid and related electrolyzed water technologies have been evaluated as potential sanitation tools within hatchery environments due to their antimicrobial properties and compatibility with a variety of application methods.

Multiple studies have investigated the use of HOCl for reducing microbial contamination on eggshell surfaces and hatchery equipment. Research has reported reductions in microorganisms of importance to poultry production, including Salmonella and E. coli, while additional studies have evaluated the role of HOCl in broader hatchery sanitation programs. Collectively, these findings have contributed to growing interest in hatchery and egg-sanitation applications. As with other poultry applications, outcomes remain dependent upon concentration, application method, contact time, organic load, and operational conditions. Nevertheless, the available evidence suggests that hatchery and egg sanitation represent relatively mature areas of poultry HOCl research and provide a strong foundation for future commercial evaluation.

5.5  Livestock Safety

Safety considerations play an important role in the evaluation of any sanitation technology used within animal-production systems. Regulatory reviews and livestock-focused technical evaluations have identified HOCl as a sanitation technology with potential applications across multiple agricultural environments. While outcomes remain dependent upon concentration, formulation, application method, and operating conditions, the available livestock literature supports continued evaluation of HOCl as one component of broader sanitation and biosecurity strategies.

5.6  Organic Load and Real-World Poultry Environments

One of the most important considerations in poultry sanitation is the presence of organic matter. Commercial poultry facilities contain manure, litter, dust, feathers, feed residue, moisture, and other materials 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 active disinfectant, and reducing contact between disinfectants and their intended microbial targets. As a result, the effectiveness observed under controlled laboratory conditions may not always translate directly to commercial poultry environments.

The influence of organic load is not unique to HOCl. Most disinfectant technologies experience some reduction in performance when exposed to significant quantities of organic matter. For this reason, poultry sanitation programs have traditionally emphasized cleaning and organic matter removal before disinfection. Mechanical removal of manure, litter, dust, and debris remains one of the most important steps in any sanitation protocol because it reduces the overall microbial burden and improves the ability of disinfectants to contact target organisms.

Several poultry studies indirectly highlight the importance of organic load. Research involving drinking-water applications demonstrated reductions in microbial loads within broiler systems, including fresh manure and cecal contents, suggesting that HOCl can remain active within complex biological environments. However, these findings should not be interpreted as evidence that HOCl can overcome heavy environmental contamination without proper cleaning.

From an operational perspective, poultry producers should view HOCl as a sanitation tool that performs best when integrated into a broader cleaning and biosecurity program. The objective is not to replace litter management, manure removal, washing procedures, or other established sanitation practices. Rather, HOCl should be evaluated as a potential means of improving microbial control after cleaning has occurred and as part of an ongoing maintenance strategy for water systems, equipment, hatcheries, and environmental sanitation programs.

5.7  Literature Gaps and Research Opportunities

The strongest evidence currently exists for drinking-water quality management, waterline sanitation, hatchery sanitation, egg sanitation, and environmental microbial control. Moderate evidence exists for poultry-house sanitation, air sanitation, and broader biosecurity applications, although outcomes are often influenced by environmental conditions and organic load. Important knowledge gaps remain regarding direct litter treatment, direct manure treatment, long-term commercial deployment, economic performance, and comparative evaluations against existing sanitation programs.

Many of the most important questions now facing poultry researchers involve implementation, economics, operational value, biofilm management, organic-load tolerance, and performance under commercial poultry-house conditions. These gaps should not be viewed as weaknesses of the technology itself. Rather, they represent opportunities for future research and field validation that will help determine where HOCl can provide the greatest practical benefit within modern poultry production systems.

6.        Research Reference Library

The research discussed throughout this report is derived from a diverse body of poultry, agricultural, veterinary, sanitation, and biosecurity 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 and maintain focus on operational and research 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, and other factors that may influence sanitation performance under commercial poultry conditions.

Readers seeking additional detail regarding specific studies, methodologies, or application areas are encouraged to review the appendices in conjunction with the relevant report sections.

7.        Operational Considerations

7.0 The Role of HOCl Within a Poultry Sanitation Program

Before evaluating the potential advantages or limitations of hypochlorous acid, it is important to understand the role it is intended to play within a poultry operation. Poultry sanitation programs consist of multiple layers, each designed to address different aspects of disease prevention, environmental management, and flock health. Cleaning, disinfection, water management, biosecurity, monitoring, and facility maintenance all contribute to the overall effectiveness of a sanitation program.

Cleaning and disinfection are often discussed together but serve different functions. Cleaning focuses on the removal of manure, litter, dust, feathers, feed residue, and other forms of organic contamination. This process reduces the overall microbial burden and improves the ability of disinfectants to contact target organisms. Disinfection focuses on reducing microbial contamination after cleaning has occurred. Because organic matter can interfere with disinfectant performance, effective cleaning remains one of the most important steps in any poultry sanitation program regardless of the disinfectant technology being used.

Within this framework, HOCl should be viewed as a sanitation and biosecurity tool rather than as a replacement for cleaning. Potential applications include environmental sanitation, drinking-water management, waterline sanitation, hatchery sanitation, egg sanitation, equipment sanitation, and broader biosecurity programs. The objective is not to eliminate existing sanitation practices but to determine whether HOCl can strengthen specific components of those programs.

The distinction is important because many of the challenges facing poultry operations originate from factors that cannot be addressed by disinfection alone. Manure accumulation, litter management, biofilm development, equipment maintenance, ventilation performance, water quality, and operational practices all influence disease pressure and sanitation outcomes. As a result, the success of any sanitation technology depends not only on antimicrobial activity but also on how effectively it can be integrated into existing management systems.

7.1 Why Poultry Operations Are Evaluating HOCl

The poultry industry has long relied on a variety of sanitation technologies, and interest in HOCl is not driven by a lack of existing disinfectants. Rather, researchers and commercial operators are evaluating whether HOCl may provide practical value within specific applications or operational environments. Particular interest has emerged in drinking-water management, waterline sanitation, hatchery sanitation, egg sanitation, environmental sanitation, and broader biosecurity programs. HOCl has been investigated across multiple poultry applications, creating the potential for a single sanitation chemistry to support several operational objectives. Researchers have also examined water quality management, biofilm control, worker handling characteristics, equipment compatibility, and implementation flexibility. While outcomes remain dependent upon operational conditions, the available literature suggests that several of these applications warrant continued evaluation and 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 poultry operations introduce variables such as water quality, organic load, application method, contact time, equipment design, environmental conditions, and operational consistency that can influence performance. Poultry studies have evaluated HOCl across a range of concentrations and delivery systems, including spraying, fogging, atomization, waterline treatment, and drinking-water applications. Consequently, successful implementation requires application-specific protocols supported by monitoring and verification activities such as environmental sampling, water-quality testing, microbial monitoring, and biofilm assessment.

7.3 Organic Matter Management Strategy

Organic matter management is one of the most important components of any poultry sanitation program. Manure, litter, dust, feathers, feed residue, and other organic materials can contribute to microbial persistence while also interfering with disinfectant performance. For this reason, poultry sanitation programs have traditionally emphasized cleaning and organic matter removal before disinfection.

A practical poultry sanitation sequence typically begins with bird removal, followed by litter removal, dry cleaning, washing, and the removal 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. Verification activities such as environmental sampling, water-quality monitoring, or visual inspection may then be used to assess sanitation effectiveness before facilities return to service.

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 litter management, 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 poultry production despite routine cleaning and disinfection efforts. Biofilms, organic load, equipment design, waterline contamination, and environmental conditions can all contribute to recurring microbial presence. For this reason, poultry researchers continue to evaluate sanitation technologies, including HOCl, as part of broader efforts to improve microbial control within commercial production systems.

7.5 Potential Advantages and Potential Limitations of HOCl

A balanced assessment of HOCl requires consideration of both potential benefits and potential limitations. The available poultry literature suggests several areas where HOCl may provide value while also identifying factors that can influence performance and implementation.

The current evidence suggests that HOCl is best viewed as a potentially useful addition to existing sanitation and biosecurity programs rather than a replacement for them.

8.        Questions for Industry Evaluation

The growing body of poultry-related HOCl research provides evidence that the technology warrants serious evaluation. However, the most important questions facing researchers and commercial operators are no longer limited to antimicrobial activity alone. Practical implementation, operational value, economic considerations, and long-term performance under commercial 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 poultry researchers, veterinarians, biosecurity specialists, and commercial operators may wish to consider when evaluating HOCl within modern poultry production systems.

8.1 Key Evaluation Considerations

When evaluating HOCl within poultry production systems, researchers should focus on practical outcomes rather than antimicrobial activity alone. Important considerations include biosecurity performance, water quality management, waterline sanitation, hatchery sanitation, environmental sanitation, operational practicality, and integration within existing management programs. Because poultry operations differ substantially in facility design, sanitation protocols, 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 poultry-management systems rather than as an isolated sanitation intervention.

8.2 What We Know and What We Still Need to Learn

One useful way to evaluate the current state of the literature is to distinguish between applications supported by stronger evidence and those that require additional investigation.

Areas Supported by Stronger Evidence

• Drinking-water quality management
• Waterline sanitation
• Hatchery sanitation
• Egg sanitation
• Environmental microbial control

Areas Supported by Moderate Evidence

• Poultry-house sanitation
• Air sanitation
• Broader biosecurity applications
• Biofilm-management programs

Areas Requiring Additional Investigation

• Direct litter treatment
• Direct manure treatment
• Long-term commercial deployment
• Economic evaluation under commercial conditions
• Comparative studies against existing sanitation programs

The existence of research gaps should not be interpreted as evidence against HOCl. Rather, these gaps help identify where future studies may provide the greatest value to poultry producers and researchers.

8.3 Proposed Poultry Field Trial Framework

The next stage of poultry HOCl research will likely depend on well-designed field trials conducted under commercial operating conditions. The objective of these trials should not be simply to confirm laboratory efficacy, but to determine where HOCl can provide practical operational value within modern poultry production systems.

Trial A – Waterline Management Program

Objective

Evaluate the impact of HOCl on waterline hygiene and biofilm management.

Potential Measurements

• Microbial counts
• Water-quality indicators
• Biofilm observations
• Maintenance requirements
• Operational consistency

Trial B – Drinking-Water Quality Program

Objective

Evaluate the influence of HOCl-treated drinking water on water hygiene and microbial indicators.

Potential Measurements

• Water-quality parameters
• Cecal microbial load
• Manure microbial load
• Water consumption
• Production performance

Trial C – Environmental Sanitation Program

Objective

Evaluate the use of HOCl for poultry-house sanitation and environmental microbial control.

Potential Measurements

• Environmental swab results
• Surface microbial counts
• ATP monitoring
• Labor requirements
• Product consumption

Trial D – Hatchery Evaluation Program

Objective

Evaluate hatchery and egg-sanitation applications under commercial operating conditions.

Potential Measurements

• Eggshell microbial counts
• Equipment sanitation results
• Environmental monitoring
• Operational practicality

Trial E – Integrated Biosecurity Program

Objective

Evaluate HOCl across multiple sanitation applications within a single operation.

Potential Measurements

1.       Waterline hygiene

2.       Environmental sanitation

3.       Operational consistency

4.       Worker observations

5.       Overall program performance

The purpose of these proposed trials is not to prescribe a specific research methodology. Rather, they provide a framework for evaluating HOCl under realistic commercial conditions where factors such as organic load, biofilm development, management practices, and operational complexity can be incorporated into the assessment process. Ultimately, these types of field studies may provide the most valuable information for determining where HOCl can deliver meaningful benefits within poultry production systems.

9.        Frequently Asked Research Questions

9.1 Can HOCl Replace Cleaning?

Answer

No. Cleaning and disinfection serve different functions within poultry sanitation programs. Cleaning removes manure, litter, dust, feathers, feed residue, and other organic contamination, while disinfection reduces microbial contamination after cleaning has occurred. HOCl should be viewed as part of a broader sanitation and biosecurity program rather than a replacement for cleaning.

Primary Reference

Block SS. Disinfection, Sterilization, and Preservation.

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9.2 Does Organic Matter Reduce the Effectiveness of HOCl?

Answer

Yes. Organic matter can consume active disinfectant, shield microorganisms, and reduce contact between disinfectants and their microbial targets. This limitation is not unique to HOCl and affects many disinfectant technologies used within animal agriculture. Cleaning and organic matter removal therefore remain essential components of poultry sanitation programs.

Primary Reference

Block SS. Disinfection, Sterilization, and Preservation.

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9.3 What Role Do Biofilms Play in Poultry Production?

Answer

Biofilms are communities of microorganisms that attach to surfaces and produce a protective matrix. They can develop on waterlines, drinkers, feeders, and equipment surfaces, making microorganisms more difficult to remove through routine sanitation. For this reason, biofilm management is an important component of poultry sanitation and waterline maintenance programs.

Primary Reference

Vestby LK et al. Biofilm Forming Abilities of Salmonella Are Correlated with Persistence in Fish Meal- and Feed Factories.

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9.4 Why Would a Poultry Operation Consider HOCl if It Already Uses Disinfectants?

Answer

Researchers are evaluating HOCl because it has been studied across multiple poultry applications, including drinking-water management, waterline sanitation, environmental sanitation, hatchery sanitation, egg sanitation, and biosecurity programs. The relevant question is not whether disinfectants already exist, but whether HOCl provides meaningful value within specific poultry applications.

Primary Reference

USDA APHIS. Hypochlorous Acid White Paper.

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9.5 Where Does the Strongest Poultry Evidence Exist Today?

Answer

The strongest evidence currently exists for drinking-water quality management, waterline sanitation, hatchery sanitation, egg sanitation, and environmental microbial control. These applications have been evaluated across multiple studies and represent some of the most mature areas of poultry HOCl research.

Primary References

Alam, M.R., et al. (2025). Controlling Microbial Population in Poultry Industry Using Acidic and Slightly Acidic Electrolysed Water as a Potential Non-Thermal Food Sanitizer.

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Li, Z., et al. (2025). Low-Concentration Hypochlorous Acid Drinking Water Alleviates Broiler Gut Microbial Load While Preserving Overall Growth Performance.

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9.6 Does HOCl Work Against Avian Influenza?

Answer

Several published studies have reported virucidal activity against avian influenza virus under controlled laboratory conditions. These findings have contributed to growing interest in HOCl as a potential component of poultry biosecurity programs, although commercial field performance remains influenced by environmental conditions and organic load.

Primary Reference

Hakim H et al. Evaluation of the Virucidal Effects of Hypochlorous Acid Against Avian Influenza Virus.

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9.7 What Evidence Exists for Drinking-Water Applications?

Answer

Drinking-water management is one of the strongest evidence areas currently available within the poultry HOCl literature. Recent broiler research reported reductions in microbial loads within cecal contents and fresh manure while maintaining overall production performance, supporting continued evaluation under commercial conditions.

Primary Reference

Zhou et al. (2025) Broiler Drinking Water Study.

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9.8 What Evidence Exists for Waterline Sanitation?

Answer

Waterline sanitation is frequently identified as one of the most practical poultry applications for HOCl. Researchers have investigated continuous treatment programs designed to support water hygiene and biofilm management within poultry water-distribution systems.

Primary Reference

Li Z., Liu C., Shao D., Tan C., Cao Y., Deng S., Lim T.T., Xu F. (2025). Low-Concentration Hypochlorous Acid Drinking Water Alleviates Broiler Gut Microbial Load While Preserving Overall Growth Performance.

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9.9 What Research Gaps Remain?

Answer

Important knowledge gaps remain regarding direct litter treatment, direct manure treatment, long-term commercial deployment, economic performance, and comparative evaluations against existing sanitation programs. These areas represent important opportunities for future field research.

Primary Reference

Alam et al. (2025). Controlling microbial population in poultry industry using acidic and slightly acidic electrolysed water as a potential non-thermal food sanitizer.

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9.10 If HOCl Works, Why Are Field Trials Still Necessary?

Answer

Laboratory studies evaluate performance under controlled conditions, whereas commercial poultry operations contain variables such as organic load, litter conditions, dust, water quality, biofilm development, ventilation systems, and management practices. Field trials help determine where HOCl provides practical value under real-world operating conditions.

Primary Reference

Hao X., Shen Z., Wang J., Zhang Q., Li B., Wang C., Cao W. (2013). Application of slightly acidic electrolyzed water for inactivating microbes in a layer breeding house.

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Appendix A – Glossary of Terms

ATP Monitoring

A testing method used to estimate biological contamination on surfaces by measuring adenosine triphosphate (ATP).

Biofilm
A community of microorganisms attached to a surface and protected by a self-produced matrix that can make sanitation more difficult.

Biosecurity
Practices designed to reduce the introduction, spread, and impact of disease-causing organisms within poultry operations.

Cecal Contents

Material contained within the ceca of poultry, often analyzed to evaluate microbial populations.

Contact Time

The period during which a disinfectant remains in contact with a surface or microorganism.

Disinfection
The process of reducing microbial contamination using chemical or physical means following cleaning.

Drinking-Water Management

Programs designed to maintain water quality and minimize microbial contamination within poultry water systems.

Environmental Sanitation

Cleaning and disinfection activities focused on poultry houses, equipment, and surrounding production environments.

Field Trial

An evaluation conducted under real-world commercial conditions rather than laboratory conditions.

Hatchery Sanitation

Sanitation practices applied to hatchery facilities, equipment, incubators, and related environments.

Hypochlorous Acid (HOCl)

A chlorine-based molecule naturally produced by the immune system and used in various sanitation and biosecurity applications.

Microbial Load

The quantity of microorganisms present within a sample, environment, or system.

Organic Load

Organic material such as manure, litter, dust, feathers, and feed residue that may interfere with disinfectant performance.

Pathogen
A microorganism capable of causing disease.

Poultry-House Sanitation

Sanitation activities conducted within commercial poultry production facilities.

Sanitation Program

A coordinated system of cleaning, disinfection, monitoring, and verification activities designed to reduce microbial contamination.

Waterline Sanitation

Cleaning and maintenance practices intended to reduce microbial contamination and biofilm formation within poultry drinking-water systems.

Appendix B – Poultry HOCl Research Catalogue

1. Air Quality and Dust Control

1.1 Application of neutral electrolyzed water spray for reducing dust levels in a layer breeding house

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Reduction of dust levels and improvement of poultry-house air quality.

1.2 Reduction of Particulate Matter and Ammonia by Spraying Acidic Electrolyzed Water onto Litter of Aviary Hen Houses: A Lab-Scale Study

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Reduction of particulate matter and ammonia within poultry housing environments.

2. Air Sanitation

2.1 A Study of Membrane-less Electrolyzed Water Fogging – Spread for Airborne Bacteria and Fungus Decontamination in Hen House

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Reduction of airborne bacteria and fungi within poultry housing.

2.2 Airborne bacterial reduction by spraying slightly acidic electrolyzed water in a laying-hen house

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Reduction of airborne bacterial contamination in laying-hen facilities.

2.3 Airborne Particulate Matter and Culturable Bacteria Reduction from Spraying Slightly Acidic Electrolyzed Water in an Experimental Aviary Laying-Hen Housing Chamber

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Reduction of airborne bacteria and particulate matter within poultry housing.

2.4 Free chlorine loss during spraying of membraneless acidic electrolyzed water and its antimicrobial effect on airborne bacteria from poultry house

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Air sanitation and airborne bacterial control during spraying operations.

2.5 Slightly acidic electrolyzed water for reducing airborne microorganisms in a layer breeding house

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Reduction of airborne microorganisms within poultry facilities.

3. Pathogen Control and Biosecurity

3.1 Evaluation of sprayed hypochlorous acid solutions for their virucidal activity against avian influenza virus through in vitro experiments

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Avian influenza biosecurity and viral control.

3.2 Preventing Salmonella Colonization of Chickens: Electrostatic Application of Electrolyzed Oxidative Acidic Water

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Prevention of Salmonella colonization within poultry flocks.

4. Drinking-Water Management

4.1 Effects of hydrogen-rich hypochlorous acid water on broiler drinking water bacterial level, growth performance, antioxidant capacity, and intestinal environment

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Drinking-water quality management, intestinal health, and production performance.

4.2 Low-Concentration Hypochlorous Acid Drinking Water Alleviates Broiler Gut Microbial Load While Preserving Overall Growth Performance

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Drinking-water quality management and microbial load reduction.

5. Egg Sanitation

5.1 Efficiency of slightly acidic electrolyzed water for inactivation of Salmonella enteritidis and its contaminated shell eggs

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Reduction of Salmonella contamination on shell eggs.

5.2 Efficacy of Slightly Acidic Electrolyzed Water for Reduction of Foodborne Pathogens and Natural Microflora on Shell Eggs

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Reduction of foodborne pathogens and natural microflora on shell eggs.

6. Environmental Sanitation

6.1 Application of slightly acidic electrolyzed water for disinfection in a broiler farm

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Farm-wide environmental sanitation and biosecurity.

6.2 Application of slightly acidic electrolyzed water for inactivating microbes in a layer breeding house

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Reduction of microbial contamination on poultry-house surfaces.

7. Hatchery Sanitation

7.1 The Use of Electrolyzed Water for Sanitation Control of Eggshells and GP Center

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Hatchery sanitation and eggshell sanitation.

8. Poultry Processing and Food Safety

8.1 Comparison of Electrolyzed Oxidizing Water with Various Antimicrobial Interventions to Reduce Salmonella Species on Poultry

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Reduction of Salmonella during poultry processing.

8.2 Controlling Microbial Population in Poultry Industry Using Acidic and Slightly Acidic Electrolysed Water as a Potential Non-Thermal Food Sanitizer

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Food safety and poultry processing sanitation.

8.3 Efficacy of Electrolyzed Water in the Prevention and Removal of Fecal Material Attachment and Its Microbicidal Effectiveness During Simulated Industrial Poultry Processing

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Removal of fecal contamination during poultry processing.

8.4 Recovery of Bacteria from Broiler Carcasses After Spray Washing with Acidified Electrolyzed Oxidizing Water

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Carcass decontamination during poultry processing.

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

Commercial poultry 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 poultry applications and operational environments.

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

Another factor driving interest is the growing body of literature supporting drinking-water and waterline applications. Poultry water systems can influence flock health, water consumption, microbial growth, and biofilm development throughout the production cycle. Because HOCl has been investigated in these systems, researchers are increasingly interested in understanding whether improvements in water hygiene 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 litter management, manure removal, washing procedures, or existing sanitation programs.

For poultry researchers and commercial operators, the key question is therefore not whether HOCl should replace existing sanitation technologies. The more relevant question is whether HOCl can provide measurable operational, biosecurity, water-management, or sanitation benefits within specific poultry applications. The available literature suggests that this question warrants continued investigation through well-designed commercial field trials.

Appendix D – Proposed Commercial Field Trial Measurements

The current poultry literature provides encouraging evidence for several HOCl applications. However, many of the most important questions facing researchers and commercial operators involve performance under real-world conditions rather than laboratory efficacy alone. The following framework identifies potential measurements that may be useful when evaluating HOCl under commercial poultry conditions.

Waterline Management Programs

Objective

Evaluate the impact of HOCl on waterline hygiene and biofilm management.

Potential Measurements

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

Drinking-Water Management Programs

Objective

Evaluate the influence of HOCl-treated drinking water on water hygiene and microbial indicators.

Potential Measurements

• Water-quality parameters
• Cecal microbial load
• Fresh manure microbial load
• Water consumption
• Flock performance indicators
• Mortality and health observations

Environmental Sanitation Programs

Objective

Evaluate the use of HOCl for poultry-house sanitation and environmental microbial control.

Potential Measurements

• Environmental swab results
• Surface microbial counts
• ATP monitoring
• Labor requirements
• Product consumption
• Sanitation verification results

Hatchery and Egg-Sanitation Programs

Objective

Evaluate hatchery and egg-sanitation applications under commercial operating conditions.

Potential Measurements

• Eggshell microbial counts
• Equipment sanitation results
• Environmental monitoring data
• Hatchery sanitation verification results
• Operational practicality
• Labor requirements

Integrated Biosecurity Programs

Objective

Evaluate HOCl across multiple sanitation applications within a single poultry operation.

Potential Measurements

• Waterline hygiene indicators
• Environmental sanitation results
• Biofilm observations
• Operational consistency
• Worker observations
• Overall program performance

Suggested Evaluation Principles

Regardless of application, future poultry field trials should attempt to evaluate HOCl under realistic commercial conditions. Factors such as organic load, litter conditions, dust levels, biofilm development, water quality, facility design, and management practices can all influence sanitation outcomes. Consequently, field studies that incorporate these variables are likely to provide more meaningful operational insights than laboratory efficacy studies alone.

The objective of future field trials should not be limited to determining whether HOCl possesses antimicrobial activity. Rather, the goal should be to identify where HOCl can provide practical, measurable, and economically justifiable value within modern poultry production systems.

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.

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