No matter where they are performed, studies with infectious agents need ironclad biorisk management. This can be promoted through robust gatekeeping of funding and publication, using a new formal reporting standard for pathogen research.

Laboratory-acquired infections and accidental pathogen escapes from laboratory settings pose biosafety risks, affecting laboratory personnel, the scientific community, the general public, animal populations, and the environment. This systematic review compares reports of laboratory-acquired infections and accidental pathogen escapes from laboratory settings in research and clinical laboratories between 2000 and 2024, identifying key risk factors. A total of 250 reports documenting 712 human cases of laboratory-acquired infections were analysed. Research laboratories reported 276 infections and eight fatalities, whereas clinical laboratories accounted for 227 infections and five deaths. Needlestick injuries and ineffective use of personal protective equipment or containment measures were major risk factors in both settings. Research laboratories frequently reported inadequate decontamination techniques, whereas improper sample handling techniques often occurred in clinical laboratories. Given that most causes of laboratory-acquired infections are unknown or under-reported, these data can inform coordinated efforts to strengthen biosafety oversight, incident reporting, and risk management to reduce biosafety lapses and ensure long-term laboratory operations.

Background: Smallpox was a major cause of human mortality until its eradication, but the threat of orthopox viruses has not disappeared. Since the eradication of smallpox and the cessation of the related vaccination campaigns, the threat has been growing, as evidenced by the currently ongoing worldwide Mpox outbreak. In addition to threats of an evolving Mpox, we must also be aware of a myriad of other threats that remain. Many countries still lack biosecurity regulations reflecting the recent technological advances, and the threat of bioterrorism remains ever present. Reconstruction of smallpox is a distinct possibility, as are other scenarios whereby other orthopox viruses may be made more fit for transmission in humans. Objectives: To outline and discuss potential biosafety and biosecurity threats posed by orthopox viruses. Sources: Published scientific literature, news articles, and international agreements. Content and implications: It would be wise to take steps to mitigate these threats now. Vaccination campaigns should be considered in areas with frequent orthopox outbreaks, and more efforts must be made to put a final end to the Mpox outbreak. In many countries, national biosafety and biosecurity regulations may need to be revised and strengthened to better reflect the threats posed by new technologies, including controls on synthesis of smallpox sequences. Furthermore, more international cooperation and aid is needed. The present global Mpox outbreak could likely have been prevented had areas where Mpox is endemic not been neglected. Future outbreaks could be much worse. Erik Boehm, Clin Microbiol Infect 2024;30:883 (c) 2024 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Background:Inactivation of infectious liquid waste can be performed by different means, including autoclaving or chemical inactivation. Autoclaving is most widely used, but cannot always be implemented, so that chemical inactivation is a possible alternative. However, its efficacy has to be proven by in-house validation. Here, we provide an easy-to-implement validation process adapted from existing standards. Methods:The bactericidal activity of two commercially available disinfectants, containing glucoprotamine or peracetic acid, was tested on two gram-positive bacteria, methicillin-resistant Staphylococcus aureus (MRSA) and Streptococcus pneumoniae (SP). Quantitative suspension tests were adapted from the European standard EN 13727. Membrane filtration was used to remove any trace of the active antiseptic. The stability of working solutions and the effect of different organic loads were also assessed. Further, the aquatic toxicity of glucoprotamine was tested on the viability and behavior of zebrafish larvae. Results:Peracetic acid was highly efficient against both strains, even at a working concentration of 0.25% for 1 minute S. pneumoniae was also highly sensitive to glucoprotamine, whereas MRSA required either higher concentrations (1%) or longer exposure times (30 min) at lower concentrations. Further, the lethal dosis that kills 50% of the embryos (LD50) for glucoprotamine was 3-3.5 mg/L using the zebrafish Embryo Acute Toxicity Test. Conclusion:We could confirm the very high efficacy of glucoprotamine- and peracetic-based disinfectants to inactivate liquid waste containing gram-positive bacteria. Also considering aquatic toxicity, this methodology could help laboratories to establish validated procedures for chemical inactivation of infectious liquid wastes relevant to their institution, balancing efficacy, and environmental issues.

Introduction: Foot and mouth disease (FMD) is a highly contagious infection of cloven-hoofed animals. The Biosafety Research Road Map reviewed scientific literature regarding the foot and mouth disease virus (FMDV). This project aims to identify gaps in the data required to conduct evidence-based biorisk assessments, as described by Blacksell et al., and strengthen control measures appropriate for local and national laboratories. Methods: A literature search was conducted to identify potential gaps in biosafety and focused on five main sections: the route of inoculation/modes of transmission, infectious dose, laboratory-acquired infections, containment releases, and disinfection and decontamination strategies. Results: The available data regarding biosafety knowledge gaps and existing evidence have been collated. Some gaps include the need for more scientific data that identify the specific safety contribution of engineering controls, support requirements for showering out after in vitro laboratory work, and whether a 3- to 5-day quarantine period should be applied to individuals conducting in vitro versus in vivo work. Addressing these gaps will contribute to the remediation and improvement of biosafety and biosecurity systems when working with FMDV.

Laboratory-acquired infections (LAIs) and accidental pathogen escape from laboratory settings (APELS) are major concerns for the community. A risk-based approach for pathogen research management within a standard biosafety management framework is recommended but is challenging due to reasons such as inconsistency in risk tolerance and perception. Here, we performed a scoping review using publicly available, peer-reviewed journal and media reports of LAIs and instances of APELS between 2000 and 2021. We identified LAIs in 309 individuals in 94 reports for 51 pathogens. Eight fatalities (2·6% of all LAIs) were caused by infection with Neisseria meningitidis (n=3, 37·5%), Yersinia pestis (n=2, 25%), Salmonella enterica serotype Typhimurium (S Typhimurium; n=1, 12·5%), or Ebola virus (n=1, 12·5%) or were due to bovine spongiform encephalopathy (n=1, 12·5%). The top five LAI pathogens were S Typhimurium (n=154, 49·8%), Salmonella enteritidis (n=21, 6·8%), vaccinia virus (n=13, 4·2%), Brucella spp (n=12, 3·9%), and Brucella melitensis (n=11, 3·6%). 16 APELS were reported, including those for Bacillus anthracis, SARS-CoV, and poliovirus (n=3 each, 18·8%); Brucella spp and foot and mouth disease virus (n=2 each, 12·5%); and variola virus, Burkholderia pseudomallei, and influenza virus H5N1 (n=1 each, 6·3%). Continual improvement in LAI and APELS management via their root cause analysis and thorough investigation of such incidents is essential to prevent future occurrences. The results are biased due to the reliance on publicly available information, which emphasises the need for formalised global LAIs and APELS reporting to better understand the frequency of and circumstances surrounding these incidents.

Introduction: The Biosafety Research Road Map reviewed the scientific literature on a viral respiratory pathogen, avian influenza virus, and a bacterial respiratory pathogen, Mycobacterium tuberculosis. This project aims at identifying gaps in the data required to conduct evidence-based biorisk assessments, as described in Blacksell et al. One significant gap is the need for definitive data on M. tuberculosis sample aerosolization to guide the selection of engineering controls for diagnostic procedures. Methods: The literature search focused on five areas: routes of inoculation/modes of transmission, infectious dose, laboratory-acquired infections, containment releases, and disinfection and decontamination methods. Results: The available data regarding biosafety knowledge gaps and existing evidence have been collated and presented in Tables 1 and 2. The guidance sources on the appropriate use of biosafety cabinets for specific procedures with M. tuberculosis require clarification. Detecting vulnerabilities in the biorisk assessment for respiratory pathogens is essential to improve and develop laboratory biosafety in local and national systems.

Introduction: Crimean Congo Hemorrhagic Fever (CCHF) virus and Lassa virus (LASV) are zoonotic agents regarded as high-consequence pathogens due to their high case fatality rates. CCHF virus is a vector-borne disease and is transmitted by tick bites. Lassa virus is spread via aerosolization of dried rat urine, ingesting infected rats, and direct contact with or consuming food and water contaminated with rat excreta.Methods: The scientific literature for biosafety practices has been reviewed for both these two agents to assess the evidence base and biosafety-related knowledge gaps. The review focused on five main areas, including the route of inoculation/modes of transmission, infectious dose, laboratory-acquired infections, containment releases, and disinfection and decontamination strategies.Results: There is a lack of data on the safe collection and handling procedures for tick specimens and the infectious dose from an infective tick bite for CCHF investigations. In addition, there are gaps in knowledge about gastrointestinal and contact infectious doses for Lassa virus, sample handling and transport procedures outside of infectious disease areas, and the contribution of asymptomatic carriers in viral circulation.Conclusion: Due to the additional laboratory hazards posed by these two agents, the authors recommend developing protocols that work effectively and safely in highly specialized laboratories in non-endemic regions and a laboratory with limited resources in endemic areas.

Introduction: Brucella melitensis and Bacillus anthracis are zoonoses transmitted from animals and animal products. Scientific information is provided in this article to support biosafety precautions necessary to protect laboratory workers and individuals who are potentially exposed to these pathogens in the workplace or other settings, and gaps in information are also reported. There is a lack of information on the appropriate effective concentration for many chemical disinfectants for this agent. Controversies related to B. anthracis include infectious dose for skin and gastrointestinal infections, proper use of personal protective equipment (PPE) during the slaughter of infected animals, and handling of contaminated materials. B. melitensis is reported to have the highest number of laboratory-acquired infections (LAIs) to date in laboratory workers.Methods: A literature search was conducted to identify potential gaps in biosafety and focused on five main sections including the route of inoculation/modes of transmission, infectious dose, LAIs, containment releases, and disinfection and decontamination strategies.Results: Scientific literature currently lacks information on the effective concentration of many chemical disinfectants for this agent and in the variety of matrices where it may be found. Controversies related to B. anthracis include infectious dose for skin and gastrointestinal infections, proper use of PPE during the slaughter of infected animals, and handling contaminated materials.Discussion: Clarified vulnerabilities based on specific scientific evidence will contribute to the prevention of unwanted and unpredictable infections, improving the biosafety processes and procedures for laboratory staff and other professionals such as veterinarians, individuals associated with the agricultural industry, and those working with susceptible wildlife species.

Introduction: Lack of evidence-based information regarding potential biological risks can result in inappropriate or excessive biosafety and biosecurity risk-reduction strategies. This can cause unnecessary damage and loss to the physical facilities, physical and psychological well-being of laboratory staff, and community trust. A technical working group from the World Organization for Animal Health (WOAH, formerly OIE), World Health Organization (WHO), and Chatham House collaborated on the Biosafety Research Roadmap (BRM) project. The goal of the BRM is the sustainable implementation of evidence-based biorisk management of laboratory activities, particularly in low-resource settings, and the identification of gaps in the current biosafety and biosecurity knowledge base.Methods: A literature search was conducted for the basis of laboratory design and practices for four selected high-priority subgroups of pathogenic agents. Potential gaps in biosafety were focused on five main sections, including the route of inoculation/modes of transmission, infectious dose, laboratory-acquired infections, containment releases, and disinfection and decontamination strategies. Categories representing miscellaneous, respiratory, bioterrorism/zoonotic, and viral hemorrhagic fever pathogens were created within each group were selected for review.Results: Information sheets on the pathogens were developed. Critical gaps in the evidence base for safe sustainable biorisk management were identified.Conclusion: The gap analysis identified areas of applied biosafety research required to support the safety, and the sustainability, of global research programs. Improving the data available for biorisk management decisions for research with high-priority pathogens will contribute significantly to the improvement and development of appropriate and necessary biosafety, biocontainment and biosecurity strategies for each agent.

Introduction:Shigella bacteria cause shigellosis, a gastrointestinal infection most often acquired from contaminated food or water. Methods:In this review, the general characteristics of Shigella bacteria are described, cases of laboratory-acquired infections (LAIs) are discussed, and evidence gaps in current biosafety practices are identified. Results:LAIs are undoubtedly under-reported. Owing to the low infectious dose, rigorous biosafety level 2 practices are required to prevent LAIs resulting from sample manipulation or contact with infected surfaces. Conclusions:It is recommended that, before laboratory work with Shigella, an evidence-based risk assessment be conducted. Particular emphasis should be placed on personal protective equipment, handwashing, and containment practices for procedures that generate aerosols or droplets.

Introduction:The SARS-CoV-2 virus emerged as a novel virus and is the causative agent of the COVID-19 pandemic. It spreads readily human-to-human through droplets and aerosols. The Biosafety Research Roadmap aims to support the application of laboratory biological risk management by providing an evidence base for biosafety measures. This involves assessing the current biorisk management evidence base, identifying research and capability gaps, and providing recommendations on how an evidence-based approach can support biosafety and biosecurity, including in low-resource settings. Methods:A literature search was conducted to identify potential gaps in biosafety and focused on five main sections, including the route of inoculation/modes of transmission, infectious dose, laboratory-acquired infections, containment releases, and disinfection and decontamination strategies. Results:There are many knowledge gaps related to biosafety and biosecurity due to the SARS-CoV-2 virus's novelty, including infectious dose between variants, personal protective equipment for personnel handling samples while performing rapid diagnostic tests, and laboratory-acquired infections. Detecting vulnerabilities in the biorisk assessment for each agent is essential to contribute to the improvement and development of laboratory biosafety in local and national systems.

Introduction: The virus formerly known as monkeypox virus, now called mpoxv, belongs to the Orthopoxvirus genus and can cause mpox disease through both animal-to-human and human-to-human transmission. The unexpected spread of mpoxv among humans has prompted the World Health Organization (WHO) to declare a Public Health Emergency of International Concern (PHEIC). Methods: We conducted a literature search to identify the gaps in biosafety, focusing on five main areas: how the infection enters the body and spreads, how much of the virus is needed to cause infection, infections acquired in the lab, accidental release of the virus, and strategies for disinfecting and decontaminating the area. Discussion: The recent PHEIC has shown that there are gaps in our knowledge of biosafety when it comes to mpoxv. We need to better understand where this virus might be found, how much of it can spread from person-to-person, what are the effective control measures, and how to safely clean up contaminated areas. By gathering more biosafety evidence, we can make better decisions to protect people from this zoonotic agent, which has recently become more common in the human population.

In the realm of high-consequence pathogens, laboratory-acquired infections (LAIs) and accidental pathogen escapes from laboratories can have far-reaching and severe implications for individuals, animals, and the environment. These occurrences are a great concern for a wide range of stakeholders, including laboratory workers, managers, those in the scientific research community and industry, policy makers, political leaders, and the general public. It is vitally important to take all necessary measures to mitigate the risks associated with such occurrences as the consequences of these events can be significant and long-lasting. Therefore, understanding the frequency and causes of laboratory accidents via the use of a systematic and transparent reporting mechanism is essential. To reduce the occurrence of accidental pathogen escapes, experts recommend implementing an evidence-based approach that prioritises risk-based biosafety, biosecurity, and biocontainment while supporting laboratory sustainability.1Kimman TG Smit E Klein MR Evidence-based biosafety: a review of the principles and effectiveness of microbiological containment measures.Clin Microbiol Rev. 2008; 21: 403-425Crossref PubMed Scopus (0) Google Scholar This method is favoured over a one-size-fits-all approach, which is often inflexible and expensive to implement and maintain. A risk-based approach to biosafety management ensures safety for staff and the community by focusing on pathogen transmission routes, manipulations or procedures, and individuals.2Kojima K Booth CM Summermatter K et al.Risk-based reboot for global lab biosafety.Science. 2018; 360: 260-262Crossref PubMed Scopus (12) Google Scholar This approach is recommended by WHO3WHOLaboratory biosafety manual, 4th edn.https://www.who.int/publications/i/item/978924001131Date: 2020Date accessed: September 18, 2023Google Scholar and the World Organisation for Animal Health,4World Organisation for Animal HealthBiosafety and biosecurity: standard for managing biological risk in the veterinary laboratory and animal facilities.in: Manual of diagnostic tests and vaccines for terrestrial animals. World Organisation for Animal Health, Paris2018: 48-63Google Scholar culminating in the Biosafety Research Road Map initiative to identify evidence gaps to guide applied biosafety research.5Blacksell SD Dhawan S Kusumoto M et al.The biosafety research road map: the search for evidence to support practices in human and veterinary laboratories.Appl Biosaf. 2023; 28: 64-71Crossref PubMed Scopus (1) Google Scholar However, resistance to change, unfamiliarity, lack of evidence, and differing understandings of the guidelines can pose challenges when implementing this approach. Furthermore, the availability of adequately trained biosafety professionals experienced in the application of this risk-based approach is frequently limited in low-resource hospital and veterinary laboratory settings. The occurrence of accidents resulting in LAIs or pathogen escapes is frequently attributed to errors or deficiencies in procedural protocols, highlighting the need for continuous improvement through root-cause analysis of the underlying causes. This approach should help to minimise the risk of LAIs and associated accidents and ensure that laboratory safety is a top priority in the future. Notably, such an approach would depend on (and promote) the formal reporting of laboratory mishaps and occurrences in a non-punitive manner. In addition, a process of documenting infectious pathogen exposure events not resulting in LAIs, together with near misses, should enhance our understanding of adverse occurrences that are preventable through mitigation-control strategies. Although many nations might be without structured and open reporting systems, where they do exist, they can serve as useful examples. In the USA, reporting of laboratory-related incidents is required under the Occupational Safety and Health Act of 1970, which requires all employers to ensure that workplaces provide safe and healthful working conditions.6Occupational Safety and Health AdministrationUS Department of LaborOccupational Safety and Health Act of 1970.https://www.osha.gov/laws-regs/oshact/completeoshactDate accessed: September 18, 2023Google Scholar Under this Act, employers are required to report illnesses and injuries, although these are not necessarily investigated. In the case of the US Federal Select Agent Program, which administers high-consequence pathogens and toxins (known as biological select agents and toxins), the regulations require the immediate reporting of exposure, LAI, or any release outside of a primary containment device.7Gonder JC Select agent regulations.ILAR J. 2005; 46: 4-7Crossref PubMed Scopus (6) Google Scholar Elsewhere, the Public Health Agency of Canada has implemented the Laboratory Incident Notification Canada surveillance system,8Thompson E El Jaouhari M Eltayeb N et al.Surveillance of laboratory exposures to human pathogens and toxins, Canada, 2021.Can Commun Dis Rep. 2022; 48: 484-491Crossref Google Scholar the Singapore Ministry of Health has the Biological Agents and Toxins Act 2005 for the reporting of adverse incidents or activities,9Singapore Ministry of HealthIncident/activities report.https://www.moh.gov.sg/biosafety/common/notifications/incident-activities-reportDate: 2019Date accessed: August 29, 2023Google Scholar and the UK's Health and Safety Executive has the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 2013.10Health and Safety ExecutiveReporting accidents and incidents at work. A brief guide to the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 2013 (RIDDOR).https://www.hse.gov.uk/pubns/indg453.pdfDate: 2013Date accessed: March 15, 2023Google Scholar To enable the greater sharing of information, these national reporting systems could inform the development of a transparent global reporting system, perhaps under the auspices of the appropriate multilateral international organisations, based on a no-blame model. Such a system could also benefit from the lessons learned from the nuclear and aircraft industries, for example, which emphasise continual improvement. On a global scale, investing in risk-based biosafety as part of a broader laboratory core management competency is of the utmost importance. However, there is a scarcity of skilled personnel with applied knowledge who can conduct risk-based assessments. Therefore, it is essential to invest in trained biosafety professionals who can advocate for adequate staffing for biosafety oversight, regulatory compliance, and transparent incident and accident reporting. The integration of accessible biosafety training programmes into higher education curricula is critical for changing the mindset and behaviour of future laboratory workers. Even in well resourced environments, the biosafety field does not have a formalised organisational structure and defined career paths, and there remains debate regarding whether credentials should be based on on-the-job experience, formal qualifications, or a combination of both.11Gillum D The making of a biosafety officer.Issues Sci Technol. 2023; 39: 67-71Crossref Google Scholar The successful implementation of global risk-based biosafety and biosecurity measures requires both political will and substantial investment in human resources and systems. Only then will a safer environment for laboratory staff and the public be achieved. The authors wish to thank David Elliott, UK International Biosecurity Programme, UK, for his input to this Comment and his contributions to the Biosafety Research Roadmap initiative. The Weapons Threat Reduction Program of Global Affairs Canada provided funding for this study. This research was funded in whole, or in part, by the Wellcome Trust (220211). The donors played no role in the writing of the manuscript or the decision to submit it for publication. We declare no competing interests. The authors alone are responsible for the views expressed in this Comment, and they do not necessarily represent the views, decisions, or policies of the institutions with which they are affiliated.

Introduction: Part 1 of this two-part series describes the use of hydrogen peroxide as a fumigant and compares it with other fumigants on the market. Technical requirements are outlined while considering physical and biological limitations of the system. This second part focuses primarily on the use of process controls to verify and validate hydrogen peroxide fumigations. Finally, a model encompassing the entire fumigation process is presented. Methods: Part 2 of the series focuses on the authors' long-time personal experiences in room and filter fumigation using various fumigation systems and is supplemented with relevant literature searches. Results: The reader is introduced to the planning and implementation of fumigation process validations. Biological indicators help users develop safe and efficient processes. Chemical indicators can be used as process controls, while measuring physical parameters will help avoid condensation of hydrogen peroxide. How many biological and chemical indicators and what type should be applied for cycle development are additionally explained. Discussion: It is important to consider numerous technical requirements when planning to implement hydrogen peroxide fumigation at an institution. Also, considerable thought needs to go into the verification and validation of the fumigation process. Conclusions: Part 1 of this series presents an overview of different fumigation systems based on hydrogen peroxide on the market and their technical requirements. Part 2 focuses on validation and verification of hydrogen peroxide fumigation while considering the entire fumigation process. The two parts together will serve users as a guide to establishing hydrogen peroxide fumigations at their facilities.

Disinfection, sterilization and waste management are key to safe handling of biological agents. It is therefore important to understand the basic mechanisms of the different methods of disinfection, sterilization and waste management that can be used in a laboratory. The specific decontamination requirements depend on the nature of the biological agents being handled. This monograph describes the methods for the management and final disposal of laboratory waste that is considered a biological hazard. The information can be used to develop standardized and more specific procedures on decontamination and waste management for a particular laboratory. The targeted readership for this monograph is personnel who perform the risk assessment, for example, laboratory managers or biosafety officers, as well as laboratory personnel and scientists who decontaminate laboratory items and workers who handle laboratory waste.The information in this monograph on decontamination and waste management is designed to accompany and support the fourth edition of the WHO Laboratory biosafety manual (core document) and other associated monographs. The manual and the monographs adopt a risk- and evidence-based approach to biosafety, rather than a prescriptive approach, in order to ensure that laboratory facilities, safety equipment and work practices are locally relevant, proportionate to needs and sustainable. Emphasis is placed on the importance of a “safety culture” that incorporates risk assessment, good microbiological practice and procedure and standard operating procedures, relevant introductory, refresher and mentoring training of personnel, and prompt reporting of incidents and accidents followed by appropriate investigation and corrective actions. This new approach aims to facilitate laboratory design and ways of operating that ensure greater sustainability while maintaining adequate and appropriate control of biosafety.The other associated monographs provide detailed information and help implement systems and strategies on the following specialized topics: risk assessment, laboratory design and maintenance, biological safety cabinets and other primary containment devices, personal protective equipment, biosafety programme management and outbreak preparedness and resilience. The monograph includes a description of the methods of decontamination used in a microbiology laboratory including handwashing, and chemical, gaseous and heat disinfection. The different classes of chemical disinfectants and their constituents, their mechanisms of action and their advantages and disadvantages are discussed. Factors that can influence the effectiveness of disinfectants are also listed. The monograph includes an overview of fumigation methods, heat inactivation and how verification of the effectiveness of these treatments is carried out by means of indicators. The monograph also covers aspects of waste management as well as documentation and record-keeping which are an integral part of waste management. Considerations for removal of both liquid and solid waste products from the laboratory and their safe disposal are described. Methods for inactivation of specimens are also discussed.

Introduction: When working with pathogens in laboratories, animal or production facilities, and even hospitals, the potential need for room fumigation for decontamination purposes must be taken into consideration. Questions regarding the choice of fumigant, technical aspects of the room, its ventilation, the fumigation system to be used, and other issues will arise and will have to be addressed. Methods: This article is based on literature searches and was compiled using the authors' long-time personal experience in room and filter fumigation using various fumigation systems. Results: The article can be used as a guide to establish an effective fumigation system in a laboratory or an animal facility setting and may be adapted for use in hospitals. Different systems for hydrogen peroxide fumigation on the market are presented. Also, technical aspects are discussed. Discussion: Hydrogen peroxide is used in various forms for fumigation of rooms, equipment, and filters. Regardless of the individual limitations of these forms, hydrogen peroxide is a versatile fumigation method. However, it is important to consider numerous technical requirements when planning to implement hydrogen peroxide fumigation at an institution. Conclusions: Subsequent to the present overview of different fumigation systems based on hydrogen peroxide on the market and their technical requirements, part 2 of this article will focus on validation and verification of hydrogen peroxide fumigation while considering the entire fumigation process. The two parts together will serve users as a guide to establishing hydrogen peroxide fumigations at their facilities.

xviiForewordThe first edition of the World Health Organization (WHO) Laboratory biosafety manualwas published in 1983. It encouraged countries to accept and implement basic concepts in biological safety and to develop national codes of practice for the safe handling of pathogenic biological agents in laboratories within their geographical borders. Since then, many countries have used the expert guidance provided in the manual to develop such codes of practice. The second and third editions of the Laboratory biosafety manual were published in 1993 and 2004 respectively. With each new version, WHO continues to provide international leadership on biosafety by addressing emerging issues, technologies and challenges, and providing guidance on best practice. Previous versions of the manual described the classification of biological agents and laboratories in terms of risk/hazard groups and biosafety/containment levels. While this may be a logical starting point for the handling and containment of biological agents, it has led to the misconception that the risk group of a biological agent directly corresponds to the biosafety level of a laboratory. In fact, the actual risk of a given scenario is influenced not only by the agent being handled, but also by the procedure being performed and the competency of the laboratory personnel engaging in the laboratory activity.This fourth edition of the manual builds on the risk assessment framework introduced in the third edition. A thorough, evidence-based and transparent assessment of the risks allows safety measures to be balanced with the actual risk of working with biological agents on a case-by-case basis. This will enable countries to implement economically feasible and sustainable laboratory biosafety and biosecurity policies and practices that are relevant to their individual circumstances and priorities.

Introduction: Formaldehyde is still the method of choice for fumigation of rooms and HEPA filters at high- and maximum-containment facilities because of its proven track record and low cost. However, formaldehyde has been shown to be carcinogenic and should ideally be replaced by other, less hazardous methods. This change has in part been hampered by the relatively high cost of alternative methods. Methods: Here, we provide examples of room fumigations using aerosolized hydrogen peroxide showing not only that it can be used economically but also that it is a versatile method and may be used under circumstances not normally suited for fumigation. Results and Discussion: Four examples of fumigation setups are presented that illustrate the versatility, ease of use, and adaptability of aerosolized hydrogen peroxide as a fumigant. In addition, we demonstrate that aerosolized hydrogen peroxide passes through HEPA filters in biological safety cabinets and individually ventilated cage racks. Conclusions: Considering that the fumigation method presented here is simple and highly effective, we expect it to serve as a relatively cost-effective alternative to formaldehyde fumigation for disinfecting potentially contaminated rooms and surfaces.

New WHO guidance could expand access to lab facilities