WHO Laboratory Biosafety Manual 4th Edition PDF

LABORATORY BIOSAFETY MANUAL FOURTH EDITION AND ASSOCIATED MONOGRAPHS LABORATORY BIOSAFETY MANUAL FOURTH EDITION LABORATORY BIOSAFETY MANUAL FOURTH EDITION AND ASSOCIATED MONOGRAPHS LABORATORY BIOSAFETY MANUAL FOURTH EDITION Laboratory biosafety manual, fourth edition (Laboratory biosafety manu...

LABORATORY BIOSAFETY MANUAL FOURTH EDITION AND ASSOCIATED MONOGRAPHS LABORATORY BIOSAFETY MANUAL FOURTH EDITION LABORATORY BIOSAFETY MANUAL FOURTH EDITION AND ASSOCIATED MONOGRAPHS LABORATORY BIOSAFETY MANUAL FOURTH EDITION Laboratory biosafety manual, fourth edition (Laboratory biosafety manual, fourth edition and associated monographs) ISBN 978-92-4-001131-1 (electronic version) ISBN 978-92-4-001132-8 (print version) © World Health Organization 2020 Some rights reserved. This work is available under the Creative Commons Attribution- NonCommercial-ShareAlike 3.0 IGO licence (CC BY-NC-SA 3.0 IGO; https://creativecommons.org/ licenses/by-nc-sa/3.0/igo). Under the terms of this licence, you may copy, redistribute and adapt the work for non-commercial purposes, provided the work is appropriately cited, as indicated below. In any use of this work, there should be no suggestion that WHO endorses any specific organization, products or services. The use of the WHO logo is not permitted. 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Design and layout by Paul Bloxham  iii Contents Acknowledgementsvi Glossary of termsx Forewordxvii SECTION 1 Introduction1 1.1 Intended scope2 1.2 How to use the Laboratory biosafety manual3 SECTION 2 Risk assessment5 2.1 Gather information9 2.2 Evaluate the risks11 2.3 Develop a risk control strategy 17 2.4 Select and implement risk control measures18 2.5 Review risks and risk control measures25 SECTION 3 Core requirements27 3.1 Good microbiological practice and procedure27 3.2 Personnel competence and training31 3.3 Facility design31 3.4 Specimen receipt and storage 34 3.5 Decontamination and waste management 35 3.6 Personal protective equipment41 3.7 Laboratory equipment43 3.8 Emergency/incident response45 3.9 Occupational health47 iv LABORATORY BIOSAFETY MANUAL – FOURTH EDITION SECTION 4 Heightened control measures49 4.1 Operational working practices and procedures49 4.2 Personnel competence and training 50 4.3 Facility design50 4.4 Specimen receipt and storage51 4.5 Decontamination and waste management51 4.6 Personal protective equipment51 4.7 Laboratory equipment54 4.8 Emergency/incident response55 4.9 Occupational health55 SECTION 5 Maximum containment measures59 5.1 Operational working practices and procedures60 5.2 Personnel competence and training60 5.3 Facility design60 5.4 Specimen receipt and storage63 5.5 Decontamination and waste management63 5.6 Personal protective equipment 63 5.7 Laboratory equipment64 5.8 Emergency/incident response64 5.9 Occupational health64 SECTION 6 Transfer and transportation65 6.1 Transfer within the laboratory65 6.2 Transfer within a building66 6.3 Transfer between buildings on the same site66 CONTENTS v 6.4 Off-site transport of infectious substances68 SECTION 7 Biosafety programme management77 7.1 Biosafety culture78 7.2 Biosafety policy78 7.3 Assigned roles and responsibilities79 7.4 Biosafety manual80 7.5 Biosafety and biosecurity risk assessment80 7.6 Supporting programmes and plans80 7.7 Reports and reviews81 SECTION 8 Laboratory biosecurity83 8.1 Biosecurity risk assessment84 8.2 Inventory control85 8.3 Information control85 8.4 Personnel control86 8.5 Physical security control86 8.6 Transport control87 8.7 Emergency/incident response87 8.8 Emerging biological risks88 8.9 Dual use research of concern89 SECTION 9 National/international biosafety oversight91 References95 Further information100 vi LABORATORY BIOSAFETY MANUAL – FOURTH EDITION Acknowledgements Principal coordinator Dr Kazunobu Kojima, World Health Organization, Switzerland Scientific contributors Mr Allan Bennett, Public Health England (WHO Collaborating Centre for Applied Biosafety and Training), United Kingdom of Great Britain and Northern Ireland Prof. Stuart Blacksell, University of Oxford/Mahidol-Oxford Tropical Medicine Research Unit, Thailand Ms Marianne Heisz, Public Health Agency of Canada (WHO Collaborating Centre for Biosafety and Biosecurity), Canada Dr Catherine Makison Booth, Health and Safety Executive, United Kingdom of Great Britain and Northern Ireland Ms Michelle McKinney, Centers for Disease Control and Prevention (WHO Collaborating Centre for Biosafety and Biosecurity), and National Institutes of Health, United States of America Dr Kathrin Summermatter, Institute for Infectious Diseases, University of Bern, Switzerland Project management Ms Lisa Stevens, World Health Organization, France Ms Rica Zinsky, World Health Organization, Switzerland Reviewers - individuals Dr Amadou Alpha Sall, Institut Pasteur de Dakar, Senegal Dr William Ampofo, Noguchi Memorial Institute for Medical Research, University of Ghana, Ghana Dr Åsa Szekely Björndal, Public Health Agency of Sweden, Sweden Dr Christina Carlson, World Health Organization, Switzerland and Centers for Disease Control and Prevention (WHO Collaborating Centre for Biosafety and Biosecurity), United States of America ACKNOWLEDGEMENTS vii Dr Mike Catton, Victorian Infectious Diseases Reference Laboratory, Peter Doherty Institute for Infection and Immunity, Australia Dr Sébastien Bruno Francois Cognat, World Health Organization, France Dr Clarissa Damaso, Federal University of Rio de Janeiro, Brazil Dr Francois Diaz, World Organisation for Animal Health, France Ms Maureen Ellis, International Federation of Biosafety Associations, Canada Dr David Franz, United States of America Dr Isabel Hunger-Glaser, Swiss Expert Committee for Biosafety, Switzerland Dr Kevin Karem, Centers for Disease Control and Prevention (WHO Collaborating Centre for Biosafety and Biosecurity), United States of America Dr Paul Meechan, Centers for Disease Control and Prevention (WHO Collaborating Centre for Biosafety and Biosecurity), United States of America Dr Masayuki Saijo, National Institute of Infectious Diseases, Japan Dr Rosemary Sang, Kenya Medical Research Institute, Kenya Dr Christina Scheel, Centers for Disease Control and Prevention (WHO Collaborating Centre for Biosafety and Biosecurity), United States of America Mr Andrew Thompson, University of Oxford, United Kingdom of Great Britain and Northern Ireland Reviewers – organizations/associations/societies/offices Internal - World Health Organization Regional Office for Africa - Mamoudou Harouna Djingarey, Yahaya Ali Ahmed, Tieble Traore, Sheick Oumar Coulibaly, Belinda Louise Herring Regional Office for the Americas - Jean-Marc Gabastou Regional Office for South-East Asia - Aparna Singh Shah, Francis Yesurajan Inbanathan Regional Office for Europe - Joanna Zwetyenga, Caroline Sarah Brown, Eugene Victor Saxentoff Regional Office for the Eastern Mediterranean – Frank Konings, Amal Barakat, Amany Ghoniem, Humayun Asghar together with Tarek Al-Sanoury, Heba Abdulridha, Rhizlane Selka viii LABORATORY BIOSAFETY MANUAL – FOURTH EDITION Regional Office for the Western Pacific – Varja Grabovac, Orla Condell, Pakapak Ketmayoon, Karen Nahapetyan WHO Antimicrobial Resistance - Carmem Lucia Pessoa da Silva WHO Emergency Preparedness Division - Jaouad Mahjour WHO Emerging and Dangerous Pathogens Laboratory Network - Pierre Formenty WHO Food safety, Zoonosis and Foodborne Disease - Jorge Raul Matheu Alvarez, Amina Benyahia Chaieb, Kazuaki Miyagishima WHO Global Outbreak Alert and Response Network - Patrick Anthony Drury WHO Global Infectious Hazards Preparedness Department - Sylvie Briand, Tim Nguyen, Matthew Lim WHO Global Influenza Programme - Magdi Samaan, Wenqing Zhang, Terry Gail Besselaar, Sandra Jackson WHO Global Malaria Programme - Andrea Bosman, Jane A. Cunningham WHO Global Tuberculosis Programme - Christopher Gilpin, Karin Weyer WHO Health Systems and Innovation - Ivana Knezevic, Tiequn Zhou, Hye-na Kang, Francis Gabriel Moussy WHO HIV/AIDS - Meg Doherty, Lara Vojnov, Silvia Bertagnolio WHO Immunization, Vaccines and Biologicals - Mick Mulders, Fatima Serhan, Deepa Sharma, Varja Grabovac, WHO Laboratory Networks – Mark Perkins, Karin von Eije, Maria van Kerkhove WHO Polio Eradication - Daphne Moffett, Nicoletta Claudia Previsani, Ousmane (Madiagne) Diop, Harpal Singh WHO Public Health Laboratory Strengthening - Virginie Dolmazon, Céline Marie Joséphine Barnadas, José Guerra, Christopher John Oxenford, Evelyne Chaignat Wyssen, Lisa Louise Carter WHO Regulation and Prequalification - Irena Prat, Mark Lanigan, Anita Sands WHO R&D Blueprint – Vaseeharan Sathiyamoorthy ACKNOWLEDGEMENTS ix External Afghanistan Biosafety Association, African Society of Laboratory Medicine, American Biological Safety Association, American Society of Microbiology, Argentina Biosafety Committee, Association for Biosafety and Biosecurity International, Association for Biosecurity in Côte d’Ivoire, Bangladesh Biosafety & Biosecurity Association, Biorisk Management Association of Kenya, Biosafety Association for Central Asia and the Caucasus, Caribbean Public Health Agency, Centre on Global Health Security - Chatham House, European Union, European Centre for Disease Prevention and Control, European Society of Clinical Microbiology and Infectious Diseases, Food and Agriculture Organization of the United Nations, Georgian Biosafety Association, Action Package Prevent 3 - Global Health Security Agenda, Hellenic Society of Biosafety, Indian Council of Medical Research, Instituto de Diagnóstico y Referencia Epidemiológicos (WHO Collaborating Center on Laboratory Biosafety), International Atomic Energy Agency, International Experts Groups of Biosafety and Biosecurity Regulators, International Federation of Biosafety Associations, International Society for Infectious Diseases, International Union of Microbiological Societies, Latin America Association for Microbiology, Malaysia Biosafety and Biosecurity Association, Manipal Academy of Higher Education (Institution of Eminence Deemed to be University), Mexican Biosafety Association, Moroccan Biosafety Association, National Institutes of Health, Netherlands Commission on Genetic Modification, Netherlands National Institute for Public Health and the Environment, Pakistan Biological Safety Association, Portuguese Laboratory Biosafety Network, Spanish Association for Biosafety, Swiss Biosafety Network, US Department of Health & Human Services, United States Centers for Disease Control and Prevention (WHO Collaborating Centre for Biosafety and Biosecurity) - Division of Select Agents and Toxins, United States Centers for Disease Control and Prevention (WHO Collaborating Centre for Biosafety and Biosecurity) - Center for Global Health, Laboratory Science, World Organisation for Animal Health Technical editing Ms Fiona Curlet Financial support Development and publication of this document have been made possible with financial support from the Global Partnership Program, Global Affairs Canada, the Biosecurity Engagement Program, United States Department of State and the Defense Threat Reduction Agency, US Department of Defense. x LABORATORY BIOSAFETY MANUAL – FOURTH EDITION Glossary of terms Acceptable risk: The risk that is considered acceptable and allows work to proceed bearing in mind the expected benefit of the planned activities. Accident: An inadvertent occurrence that results in actual harm such as infection, illness, injury in humans or contamination of the environment. Aerosol: Liquid or solid particles suspended in air and of a size that may allow inhalation into the lower respiratory tract (usually less than 10 micrometres in diameter). Aerosol/airborne transmission: The spread of infection caused by the inhalation of aerosols. Aerosol-generating procedure: Any procedure that intentionally or inadvertently results in the creation of liquid or solid particles, which become suspended in the air (aerosols). Aseptic techniques: Conditions and procedural measures designed to effectively prevent contamination. Biological agent: A microorganism, virus, biological toxin, particle or otherwise infectious material, either naturally occurring or genetically modified, which may have the potential to cause infection, allergy, toxicity or otherwise create a hazard to humans, animals, or plants. Biological safety cabinet (BSC): An enclosed, ventilated working space designed to provide protection to the operator, the laboratory environment and/or the work materials for activities where there is an aerosol hazard. Containment is achieved by segregation of the work from the main area of the laboratory and/or through the use of controlled, directional airflow mechanisms. Exhaust air is passed through a high efficiency particulate air (HEPA) filter before recirculating into the laboratory or into the building’s heating, ventilation and air conditioning system. There are different classes (I, II and III) of BSCs that provide different levels of containment. Biosafety: Containment principles, technologies and practices that are implemented to prevent unintentional exposure to biological agents or their inadvertent release. Biosafety committee: An institutional committee created to act as an independent review group for biosafety issues, reporting to senior management. The membership of the biosafety committee should reflect the different occupational areas of the organization as well as its scientific expertise. GLOSSARY OF TERMS xi Biosafety officer: An individual designated to oversee facility or organizational biosafety (and possibly biosecurity) programmes. The person fulfilling this function may also be termed biosafety professional, biosafety advisor, biosafety manager, biosafety coordinator, or biosafety management advisor. Biosafety programme management: The development, implementation and oversight of biosafety at the organizational level using a variety of information that includes institutional policies, guidance documents for practices and procedures, planning documents (training, recruitment, emergency/incident response) and record keeping (personnel, inventories, incident management). Biosecurity: Principles, technologies and practices that are implemented for the protection, control and accountability of biological materials and/or the equipment, skills and data related to their handling. Biosecurity aims to prevent their unauthorized access, loss, theft, misuse, diversion or release. Calibration: Establishment of the relationship between the measurement provided by the instrument and the corresponding values of a known standard, allowing correction to improve accuracy. For example, laboratory equipment such as pipetting devices may need calibration periodically to ensure proper performance. Certification: A third-party testimony based on a structured assessment and formal documentation confirming that a system, person or piece of equipment conforms to specified requirements, for example, to a certain standard. Code of practice (code of conduct, code of ethics): Non-legislated guidelines for behavioural and practical standards that are voluntarily accepted as best practice and are thus followed by one or more organizations and/or individuals. Communicability: Capability of a biological agent to be transmitted from one person or animal to another, either through direct or indirect transmission. This is often related to/represented by an epidemiological measurement called the basic reproduction number (R0) which is an average number of secondary infections generated by a single infected individual in a fully susceptible population. Consequence (of a laboratory incident): The outcome of an incident (exposure to and/ or release of a biological agent) of varying severity of harm, occurring in the course of laboratory operations. Consequences may include a laboratory-associated infection, other illness or physical injury, environmental contamination, or asymptomatic carriage of a biological agent. Containment: The combination of physical design parameters and operational practices that protect personnel, the immediate work environment and the community from exposure to biological agents. The term "biocontainment" is also used in this context. xii LABORATORY BIOSAFETY MANUAL – FOURTH EDITION Core requirements: A set of minimum requirements defined in the fourth edition of the World Health Organization (WHO) Laboratory biosafety manual to describe a combination of risk control measures that are both the foundation for, and an integral part of, laboratory biosafety. These measures reflect international standards and best practice in biosafety that are necessary to work safely with biological agents, even where the associated risks are minimal. Decontamination: Reduction of viable biological agents or other hazardous materials on a surface or object(s) to a pre-defined level by chemical and/or physical means. Disinfectants: Agents capable of eliminating viable biological agents on surfaces or in liquid waste. These will have varying effectiveness depending on the properties of the chemical, its concentration, shelf life and contact time with the agent. Disinfection: A process to eliminate viable biological agents from items or surfaces for further safe handling or use. Droplets: A suspension of particles, normally defined as more than 10 micrometres in diameter, which tends to fall out of the air resulting in contamination of nearby surfaces. Dual use items: Certain materials, information and technologies that are intended for benefit, but which might be misapplied to do harm. Emergency/incident response: An outline of the behaviours, processes and procedures to be followed when handling sudden or unexpected situations, including exposure to or release of biological agents. The goal of an emergency/incident response is to prevent injuries or infections, reduce damage to equipment or the environment, and accelerate resumption of normal operations. Endemic disease: A disease naturally occurring in a particular region or population. Engineering controls: Risk control measures that are built into the design of a laboratory or laboratory equipment to contain the hazards. Biological safety cabinets (BSCs) and isolators are forms of engineering control in order to minimize the risk of exposure to and/or unintended release of biological agents. Exotic disease: A disease not normally occurring in a particular region or area, often imported from another area. It can also be referred to as non-indigenous disease. Exposure: An event during which an individual comes in contact with, or is in close proximity to, biological agents with the potential for infection or harm to occur. Routes of exposure can include inhalation, ingestion, percutaneous injury and absorption and are usually dependent upon the characteristics of the biological agent. However, some infection routes are specific to the laboratory environment and are not commonly seen in the general community. GLOSSARY OF TERMS xiii Good microbiological practice and procedure (GMPP): A basic laboratory code of practice applicable to all types of laboratory activities with biological agents, including general behaviours and aseptic techniques that should always be observed in the laboratory. This code serves to protect laboratory personnel and the community from infection, prevent contamination of the environment, and provide protection for the work materials in use. Hazard: An object or situation that has the potential to cause adverse effects when an organism, system or (sub)population is exposed to it. In the case of laboratory biosafety, the hazard is defined as biological agents which have the potential to cause adverse effects to personnel and/or humans, animals, and the wider community and environment. A hazard does not become a “risk” until the likelihood and consequences of that hazard causing harm are taken into account. Heightened control measures: A set of risk control measures as described in the WHO Laboratory biosafety manual that may need to be applied in a laboratory facility because the outcome of a risk assessment indicates that the biological agents being handled and/or the activities to be performed with them are associated with a risk that cannot be brought below an acceptable risk with the core requirements only. Inactivation: Removal of the activity of biological agents by destroying or inhibiting reproductive or enzyme activity. Incident: An occurrence that has the potential to, or results in, the exposure of laboratory personnel to biological agents and/or their release into the environment that may or may not lead to actual harm. Infectious dose: The amount of biological agent required to cause an infection in the host, measured in number of organisms. Often defined as the ID50, the dose that will cause infection in 50% of those exposed. Infectious substances: The term applied for the purposes of transport to any material, solid or liquid, which contains biological agents capable of causing infection in either humans, animals or both. Infectious substances can include patient specimens, biological cultures, medical or clinical wastes and/or biological products such as vaccines. Initial risk: Risk associated with laboratory activities or procedures that are conducted in the absence of risk control measures. Laboratory-associated infection: Any infection acquired or reasonably assumed as a result of exposure to a biological agent in the course of laboratory-related activities. A person-to-person transmission following the incident may result in linked secondary cases. Laboratory-associated infections are also known as laboratory-acquired infections. Likelihood (of a laboratory incident): The probability of an incident (that is exposure to and/or a release of a biological agent) occurring in the course of laboratory work. xiv LABORATORY BIOSAFETY MANUAL – FOURTH EDITION Maximum containment measures: A set of highly detailed and stringent risk control measures described in the fourth edition of the WHO Laboratory biosafety manual that are considered necessary during laboratory work where a risk assessment indicates that the activities to be performed pose very high risks to laboratory personnel, the wider community and/or the environment, and therefore an extremely high level of protection must be provided. These are especially needed for certain types of work with biological agents that may have catastrophic consequences if an exposure or release were to occur. One Health: An approach to designing and implementing programmes, policies, legislation and research in which multiple sectors communicate and work together to achieve better public health outcomes. The areas of work in which a One Health approach is particularly relevant include food safety, the control of zoonoses, and combatting antibiotic resistance. Pathogen: A biological agent capable of causing disease in humans, animals or plants. Personal protective equipment (PPE): Equipment and/or clothing worn by personnel to provide a barrier against biological agents, thereby minimizing the likelihood of exposure. PPE includes, but is not limited to, laboratory coats, gowns, full-body suits, gloves, protective footwear, safety glasses, safety goggles, masks and respirators. Primary containment device (equipment): A contained workspace designed to provide protection to its operator, the laboratory environment and/or the work materials for activities where there is an aerosol hazard. Protection is achieved by segregation of the work from the main area of the laboratory and/or through the use of controlled, directional airflow mechanisms. Primary containment devices include biological safety cabinets (BSCs), isolators, local exhaust ventilators and ventilated working spaces. Propagation: The action of intentionally increasing or multiplying the number of biological agents. Prophylaxis: Treatment given to prevent infection or to mitigate the severity of the disease if infection were to occur. It can be delivered before possible exposure or after exposure before the onset of infection. Redundancy: Repetitions of systems or parts of a system to provide protection in the case of a primary system failure. For example, a series of high efficiency particulate air (HEPA) filters in case one or more fail when used to move laboratory air to the outside environment. Residual risk: Risk that remains after carefully selected risk control measures have been applied. If residual risk is not acceptable, it may be necessary to apply additional risk control measures or to stop the laboratory activity. Risk: A combination of the likelihood of an incident and the severity of the harm (consequences) if that incident were to occur. GLOSSARY OF TERMS xv Risk assessment: A systematic process of gathering information and evaluating the likelihood and consequences of exposure to or release of workplace hazard(s) and determining the appropriate risk control measures to reduce the risk to an acceptable risk. Risk communication: An interactive and systematic process to exchange information and opinion on risk(s) that inclusively engages all relevant personnel of various categories as well as community leaders and officials where appropriate. Risk communication is an integral and ongoing part of the risk assessment, soliciting clear understanding of the risk assessment process and outcomes, aiming at proper implementation of risk control measures. Decisions on risk communication, including what, whom and how, should be part of an overall risk communication strategy. Risk control measure: Use of a combination of tools, which include communication, assessment, training, and physical and operational controls, to reduce the risk of an incident/event to an acceptable risk. The risk assessment cycle will determine the strategy that should be used to control the risks and the specific types of risk control measures required to achieve this. Risk evaluation: Part of risk assessment where the likelihood of exposure to a hazard is weighed against the potential severity of harm under a set of predefined circumstances, such as a specific laboratory procedure. The goal of a risk evaluation is to determine whether the assessed risk is acceptable, or whether further targeted risk control measures should be implemented to prevent or reduce the risks. Safety culture: A set of values, beliefs and patterns of behaviour instilled and facilitated in an open and trusting atmosphere by individuals and organizations working together to support or enhance best practice for laboratory biosafety, irrespective of whether it is stipulated in applicable codes of practice and/or regulations. Sharps: Any device or object that is a puncture or wound hazard because of its pointed ends or edges. In the laboratory, sharps can include needles, syringes with attached needles, blades, scalpels or broken glass. Standard operating procedures (SOPs): A set of well-documented and validated stepwise instructions outlining how to perform laboratory practices and procedures in a safe, timely and reliable manner, in line with institutional policies, best practice and applicable national or international regulations. Sterile: The state of having a complete absence of viable biological agents and spores. Sterilization: A process that kills and/or removes all biological agents including spores. Transmission: The transfer of biological agent(s) from objects to living things, or between living things, either directly or indirectly via aerosols, droplets, body fluids, vectors, food/water or other contaminated objects. xvi LABORATORY BIOSAFETY MANUAL – FOURTH EDITION Validation: Systematic and documented confirmation that the specified requirements are adequate to ensure the intended outcome or results. For example, in order to prove a material is decontaminated, laboratory personnel must validate the robustness of the decontamination method by measurement of the remaining biological agents against the detection limit by chemical, physical or biological indicators. Verification: Confirmation that a given item (product, process or system) satisfies the specified requirements. For example, verification that the performance of an autoclave meets the standards specified by the manufacturer should be performed periodically. Zoonotic disease (zoonosis): Infectious disease that is naturally transmitted from animals to humans and vice versa.  xvii Foreword The first edition of the World Health Organization (WHO) Laboratory biosafety manual was 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. xviii LABORATORY BIOSAFETY MANUAL – FOURTH EDITION  1 INTRODUCTION SECTION 1 Laboratory biosafety and biosecurity activities are fundamental to protecting the laboratory workforce and the wider community against unintentional exposures or releases of pathogenic biological agents. These activities are implemented using a risk assessment framework and through the development of a safety culture which is needed to ensure a safe workplace where adequate measures are applied to minimize the likelihood and severity of any potential exposure to biological agents. Biosafety awareness and expertise have improved greatly since previous editions of the World Health Organization’s (WHO) Laboratory biosafety manual (1-3). New technologies, such as the use of molecular methods, have advanced considerably and reduced the number of diagnostic activities that require propagation of high titre biological agents. A review of recent laboratory-associated infections showed that most were caused by human factors rather than malfunctions of engineering controls (4,5). Factors that have led to potential and confirmed exposures to biological agents include an absence or improper use of personal protective equipment (PPE) (6,7), inadequate or ignored risk assessments (8), lack of standard operating procedures (SOPs) (9), needlestick injuries (10,11) and/or insufficiently trained personnel (12). It can be argued, therefore, that the best designed and most well engineered laboratory is only as good as its least competent worker. The need to update international laboratory biosafety guidance is part of a broader initiative to globalize biosafety and emphasize the principles and approaches that are accessible to countries with a broad range of financial, technical and regulatory resources. WHO revised the International Health Regulations in 2005 “to help the international community to prevent and respond to acute public health risks that have the potential to cross borders and threaten people worldwide” (13). These regulations require all 196 WHO States Parties to be well prepared for potential outbreaks and new diseases; this includes early diagnosis and confirmation by laboratories to facilitate infection prevention and control. Biosafety and biosecurity are also one of the technical areas assessed by the monitoring and evaluation framework of the International Health Regulations. This indicates that safe and secure laboratory operations are essential components of compliance with the International Health Regulations and prevention of acute public health threats. This edition of the manual aims to guide sustainable developments in biosafety, including a national oversight system, training, best working practices and a risk assessment framework to promote a responsible safety culture that builds country capacity and complies with the International Health Regulations. 2 LABORATORY BIOSAFETY MANUAL – FOURTH EDITION 1.1 Intended scope This fourth edition of the WHO Laboratory biosafety manual (LBM4) adopts 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 and sustainable. Emphasis is placed on the importance of a “safety culture” that incorporates risk assessment, good microbiological practice and procedure (GMPP) and SOPs, appropriate 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 that ensures greater sustainability while maintaining an appropriate control of biosafety. For veterinary laboratories, this risk-based approach complements the recently revised World Organisation for Animal Health (OIE) standard for managing biological risk in the veterinary laboratory and animal facilities (14). The fourth edition of the manual provides a risk-based, technology-neutral and cost-effective approach to biosafety, with guidance on the feasibility of laboratory operations even in resource-limited settings. This approach lays a foundation for equitable access to clinical and public health laboratory tests, and encourages biomedical research opportunities, which are increasingly important to combat infectious disease outbreaks, without compromising safety. The manual also provides an overview of biosecurity; however, this subject is covered in detail in another WHO guidance document (15). It does not cover animal pathogens unless they are zoonotic. For animal pathogens, reference should be made to the OIE standard for managing biological risks in the veterinary laboratories and animal facilities (14). This publication provides guidance specifically for those who work with biological agents or in facilities where personnel may be exposed to potentially infectious substances that present a hazard to human health. It can be used to drive a safety culture for every day laboratory practices and procedures. It will also be of value to those building or renovating laboratory facilities and to countries developing or implementing biosafety programmes and national-level frameworks for biosafety oversight. While the primary scope of this manual is laboratory biosafety as it pertains to the handling, management, and containment of biological agents and materials that pose a threat to human health, it is important to note that health and safety risk factors that are 1) related to biological agents and materials hazardous to plants, animals, and/or the environment and 2) not related to biological agents and materials should also be assessed because such hazards also exist in a laboratory setting. The risk- and evidence-based approach to biosafety and biosecurity of biological agents and materials outlined in the LBM4 can also be applied to risk management of non-biological hazards such as chemicals, physical hazards, adverse ergonomic conditions, allergens, and a broad range of psychosocial factors (for example, work- related stress) as well as biological hazards that pose an actual or potential threat to animal or environmental health, such as arthropod vectors containing gene drives for sterilization or transgenic laboratory animals with increased susceptibility to endemic or circulating biological agent(s). SECTION 1 INTRODUCTION 3 Such broad application of the guidance outlined in the LBM4 facilitates a comprehensive, integrated approach to laboratory biosafety and biosecurity and promotes responsible laboratory use of biological agents and materials. Guidance documents and international best practice should be consulted for additional information in these areas (16). 1.2 How to use the Laboratory biosafety manual This manual should complement any national regulation and oversight mechanisms that may be in place, and be used to assess, control and review risks at the local level. Therefore, the document covers the following areas: n risk assessment, control and review, n core requirements for biosafety, n options for heightened control measures, n maximum containment measures for very high-risk operations, n transfer and transportation of infectious substances, n biosafety programme management, n laboratory biosecurity, and n national and international biosafety oversight. Associated monographs have also been produced to provide more detailed informa- tion and help implement systems and strategies on specialized topics. It is anticipated that this core document will be read first and the associated monographs can be referred to when more detailed information is required. The monographs include: n biosafety programme management (17), n risk assessment (18), n biological safety cabinets and other primary containment devices (19), n personal protective equipment (20), n laboratory design and maintenance (21), n decontamination and waste management (22), and n outbreak preparedness and resilience (23). 4 LABORATORY BIOSAFETY MANUAL – FOURTH EDITION  5 RISK ASSESSMENT SECTION 2 As described in the sections below, the control of biological risks - whether at national or organizational levels - is informed by performing a risk assessment. Risk assessment is the term used to describe the stepwise process in which the risk(s) arising from working with a hazard(s) are evaluated and the resulting information is used to determine whether risk control measures can be applied to reduce those risks to acceptable risks. Risk is the combination of the probability that a hazard will cause harm and the severity of harm that may arise from contact with that hazard. In the case of laboratory biosafety, the hazards are biological agents whose pathogenic characteristics give them the potential to cause harm to humans or animals should they be exposed to these agents. The harm caused by exposure to biological agents can vary in nature and can range from an infection or injury to a disease or outbreak in larger populations (see Box 2.1). BOX 2.1 LIKELIHOOD AND CONSEQUENCE FOR LABORATORY BIOSAFETY In the context of laboratory biosafety, likelihood refers to the potential for an exposure and/or a release outside of the laboratory. Consequence refers to the severity of the outcome from an exposure, if it were to occur. This could include a laboratory-associated infection, asymptomatic carriage, environmental contamination, spread of disease throughout the surrounding community or other illness or injury. For this reason, factors that contribute to the occurrence of infection, such as routes of transmission, infectious dose and communicability, need to be considered in relation to the consequence of an exposure or release. 6 LABORATORY BIOSAFETY MANUAL – FOURTH EDITION It is important to note that hazards alone do not pose a risk to humans or animals. For example, a vial of blood containing a biological agent such as Ebola virus does not pose a risk to the laboratory personnel until they come into contact with the blood contained within the vial. Therefore, the true risk associated with a biological agent cannot be determined by only identifying its pathogenic characteristics. Consideration must also be given to the types of procedure(s) that will be performed with the biological agent and the environment in which these procedures will take place. Any facility that handles biological agents has an obligation to their personnel and the community to perform a risk assessment on the work they will conduct and to select and apply appropriate risk control measures to reduce those risks to an acceptable risk. The purpose of the risk assessment is to gather information, evaluate it and use it to inform and justify the implementation of processes, procedures and technologies to control the risks present. Analysis of this information empowers laboratory personnel as it gives them a deeper understanding of the biological risks and the ways in which they can affect them. It helps create shared values, patterns of behaviour and perceptions of the importance of safety, and makes laboratory personnel more likely to conduct their work safely and maintain a safety culture in the laboratory. Risk assessments must always be conducted in a standardized and systematic way to ensure they are repeatable and comparable in the same context. For this reason, many organizations offer risk assessment templates, checklists or questionnaires that provide stepwise approaches to identify, evaluate and determine risks associated with the hazards present, before using this information to identify appropriate risk control measures (24, 25). The various steps of the risk assessment process collectively form a risk assessment framework (Figure 2.1). Figure 2.1 The risk assessment framework  SECTION 2 RISK ASSESSMENT 7 Where Figure 2.1 illustrates the steps in the risk assessment framework, Table 2.1 provides an overview of the key considerations that apply during each step of the cycle. It is important to note that not all factors will affect risk in the same way, but each should be carefully considered. When conducting a risk assessment, it must be remembered that the risk is not based on the pathogenicity of the biological agent alone, but on the likelihood and consequence of an incident occurring – in other words, the risk of exposure to and/or release of the biological agent during laboratory operations. Table 2.1 Key considerations in the risk assessment framework STEP KEY CONSIDERATIONS 1. Gather information § What biological agents will be handled and what are their (hazard identification) pathogenic characteristics? § What type of laboratory work and/or procedures will be conducted? § What type(s) of equipment will be used? § What type of laboratory facility is available? § What human factors exist (for example, what is the level of competency of personnel)? § What other factors exist that might affect laboratory operations (for example, legal, cultural, socioeconomic, public perception)? 2. Evaluate the risks § How could an exposure and/or release occur? § What is the likelihood of an exposure and/or release? § What information gathered influences the likelihood the most? § What are the consequences of an exposure and/or release? § Which information/factor influences the consequences the most? § What is the overall initial risk of the activities? § What is an acceptable risk? § Which risks are unacceptable? § Can unacceptable risks be controlled, or should the work not proceed at all? 3. Develop a risk control § What resources are available for risk control measures? strategy § What risk control strategies are most applicable for the resources available? § Are resources sufficient to obtain and maintain those risk control measures? § Are proposed control strategies effective, sustainable and achievable in the local context? 8 LABORATORY BIOSAFETY MANUAL – FOURTH EDITION Table 2.1 Key considerations in the risk assessment framework (continued) STEP KEY CONSIDERATIONS KEY CONSIDERATIONS 4. Select and implement risk § Are there any national/international regulations requiring control measures prescribed risk control measures? § What risk control measures are locally available and sustainable? § Are available risk control measures adequately efficient, or should multiple risk control measures be used in combination to enhance efficacy? § Do selected risk control measures align with the risk control strategy? § What is the residual risk after risk control measures have been applied and is it now acceptable? § Are additional resources required and available for the implementation of risk control measures? § Are the selected risk control measures compliant with national/international regulations? § Has approval to conduct the work been granted? § Have the risk control strategies been communicated to relevant personnel? § Have necessary items been included in the budget and purchased? § Are operational and maintenance procedures in place? § Have personnel been appropriately trained? 5. Review risks and risk § Have there been any changes in activities, biological control measures agents, personnel, equipment or facilities? § Is there any new knowledge available of biological agents and/or the processes being used? § Are there any lessons learnt from incident reports and investigations that may indicate improvements to be made? § Has a periodic review cycle been established? It should be noted that laboratories worldwide could face unique challenges that will influence how various parts of the risk assessment framework are conducted. Challenges may include: the level of organizational and financial resources available to manage biological risks; absence of a reliable electrical supply; inadequate facility infrastructure; severe weather; under-staffed laboratories; and under-trained personnel. Furthermore, the status of national regulatory frameworks may influence the way in which risks are identified and controlled at a level higher than laboratory management, and compliance with any regulations should be a primary focus. For these reasons, the results of a risk assessment and the risk control measures implemented may vary considerably from laboratory to laboratory, institution to institution, region to region and country to country.  SECTION 2 RISK ASSESSMENT 9 The following subsections describe in more detail the activities in each step of the risk assessment framework. They provide an overview of the most important components of risk assessments and the key considerations for conducting them. More detailed information on additional considerations and relevant templates can be found in Monograph: risk assessment (18). 2.1 Gather information Those conducting a risk assessment must collect and consider a wide range of information in order to accurately evaluate the risks and appropriately select the risk control measures needed to reduce risks to acceptable risks in the laboratory. This information goes beyond identifying the hazards – the biological agents being used – and considers the procedural and contextual situations that contribute to the overall risk (26). Key information to be gathered should include, for example: n laboratory activities planned (for example, procedures, equipment, animal work, sonication, aerosolization and centrifugation), n competency of the personnel carrying out the work, n concentration and volume of the biological agent and potentially infectious material to be manipulated, n potential routes of transmission, n infectious dose of the biological agent, n communicability of the biological agent, n severity of infection with the biological agent, n local availability of effective prophylaxis or therapeutic interventions, n stability of the biological agent in the laboratory and external environment, n susceptibility of laboratory personnel (for example, at-risk individuals), n range of hosts of the biological agent (that is zoonotic potential), n endemicity of the biological agent in the local population, n frequency of equipment and building failures (for example, power, building infrastructure and systems). 10 LABORATORY BIOSAFETY MANUAL – FOURTH EDITION All of the above-mentioned information collectively informs a much broader, multifactorial evaluation of risk that may exist in the laboratory. Information on all of these factors is essential as various combinations of biological agents and activities may pose greater risks in some situations than in others. For example, culturing a biological agent with a low infectious dose that is transmissible by the aerosol route might have a greater risk than culturing another biological agent with a high infectious dose that is only transmissible by the oral route. Or, performing research on a biological agent that is not prevalent in the local community will pose a greater risk than performing the work in a region where it is endemic. It is important to remember that gathering information should also include defining the attributes of the laboratory environment, such as the condition of the building and laboratory areas where the work will be conducted. Improperly maintained structures can contribute to increased risks by increasing the probability of breakages or failures of features such as waste disposal or ventilation systems. Cracks in flooring and bench tops make disinfecting laboratory surfaces difficult, and can contribute to slips, trips, falls and dropped items containing biological agents. Finally, information on human factors should also be considered, because the competence of laboratory personnel and their ability to follow established biosafety practice and procedure (in particular GMPP) are likely to have the greatest influence on the likelihood of incidents. Even the best designed and constructed facility or the most sophisticated equipment can only confer safety to its user if he/she is able to operate it correctly through proper training and proficiency practices. 2.1.1 Information on new or unknown biological agents Where new biological agents are being used, or there are specimens for which detailed data are unknown, the information available may be insufficient to be able to carry out a comprehensive risk assessment. This applies to clinical specimens collected in the field during potential outbreak investigations. In such cases, it is sensible to take a cautious approach to specimen manipulation and handle all materials as potentially infectious. More information about biosafety in outbreak situations can be found in Monograph: outbreak preparedness and resilience (23). Certain information should be requested, where possible, to assist in determining the risks associated with handling such specimens including: n medical data on the patient from whom the specimen was taken, n epidemiological data (severity and mortality data, suspected route of transmission, other outbreak investigation data), and n information on the geographical origin of the specimen.  SECTION 2 RISK ASSESSMENT 11 In the case of an outbreak of a disease of unknown etiology, appropriate ad hoc guidelines can be produced and posted by competent national authorities and/ or WHO to indicate how specimens are to be handled safely. This may include how specimens should be prepared for shipment as well as specific risk control measures that should be implemented. 2.2 Evaluate the risks After gathering all available information on the circumstances of the work to be performed, it is necessary to use that information to identify and evaluate any risks that exist. The goal of the risk evaluation step is to: n determine the likelihood of an exposure to and/or release of a biological agent occurring and the severity of the consequences of such an event, n establish how the likelihood and consequence contribute to the initial risk of the work to be performed, n decide, based on the gathered information of the risk assessment, whether these risks are acceptable or not; this decision must be justified and documented comprehensively. If the evaluated risks are not acceptable, those performing the risk assessment should proceed to step 3 of the risk assessment framework and develop an appropriate risk control strategy, unless it is decided not to undertake the work at all. The primary considerations required during this risk evaluation step are outlined in the subsections below. 2.2.1 Determine the likelihood and consequences Evaluation of the information gathered should first include the determination of likelihood of an exposure to and/or release of a biological agent occurring, and of the severity of the associated consequences. It is these factors, when considered together, that will ultimately determine the overall, or initial, risk of the situation for which the information has been gathered. This is illustrated in Box 2.2. 12 LABORATORY BIOSAFETY MANUAL – FOURTH EDITION BOX 2.2 EXAMPLE OF HOW LIKELIHOOD AND CONSEQUENCE INFLUENCE RISK Cigarette smoke is a common hazard. The likelihood of exposure to cigarette smoke will differ depending on the situation. It will be greatest for an individual smoking a cigarette, moderate for those exposed to a smoker’s second-hand smoke, and lowest for someone with respiratory protection or in smoke-free zones. The consequences of exposure to cigarette smoke will range from mild nausea and respiratory irritation to various cardiac and pulmonary diseases to cancer and even death depending on the toxicity of the cigarette, frequency and duration of exposure and other factors related to human susceptibility. Both likelihood and consequence must be considered when evaluating the risks associated with cigarette smoke. This example also shows how individuals evaluate and accept risk differently, given how prevalent smoking is despite the potential negative consequences. A similar risk assessment process for working with biological agents in the laboratory, weighing likelihood and consequence, is outlined in this section. Examples of factors that can elevate the likelihood of an exposure to and/or release of biological agents during work in the laboratory, and/or escalate its associated consequences are given in Tables 2.2 to 2.4. A low infectious dose is associated with a greater consequence from an exposure as the amount of the biological agent needed to cause a laboratory-associated infection is small. However, a low infectious dose does not affect the likelihood that an exposure occurs; this relies on factors associated with the work (Table 2.2). SECTION 2 RISK ASSESSMENT 13 Table 2.2 Factors that affect the likelihood of an incident occurring FACTORS ASSOCIATED WITH RATIONALE HIGH LIKELIHOOD OF INCIDENTS OCCURRING Laboratory activities associated with When aerosols are generated by these aerosolization (for example, sonication, methods, the likelihood of exposure through homogenization, centrifugation) inhalation is increased, as is the likelihood of release of these aerosols into the surrounding environment where they might contaminate laboratory surfaces and also spread into the community. Laboratory activities associated with sharps When activities involve work with sharps, the materials likelihood of percutaneous exposure to a biological agent through a puncture wound is increased. Low competency of personnel carrying out Low proficiency of personnel in laboratory the work processes and procedures, through lack of experience, understanding or failure to comply with SOPs and GMPP, can lead to errors in performing the work which are more likely to result in exposure to and/or release of a biological agent. Cleaning and maintenance personnel must be trained before working close to a biological agent. Highly environmentally stable biological Biological agents that have settled agents on laboratory surfaces (for example, contamination caused by poor technique that allowed settling of aerosol or droplets after release) can be a source of inadvertent exposure as long as they remain stable in the environment, even if the contamination cannot be seen. Inadequate or poor availability of electrical All these factors may result in partial breaches power, dilapidated laboratory facilities and in, or complete failure of, biocontainment building systems, malfunctioning equipment, systems designed to reduce the likelihood damage from frequent severe weather and of exposure to and/or release of biological access of insects and rodents to the agents. laboratory. GMPP = good microbiological practice and procedure; SOPs = standard operating procedures. 14 LABORATORY BIOSAFETY MANUAL – FOURTH EDITION Table 2.3 Factors that affect the consequences of an incident if it were to occur FACTORS ASSOCIATED WITH RATIONALE GREATER CONSEQUENCES IF AN INCIDENT WERE TO OCCUR Low infectious dose For infection to occur in an exposed individual, a certain quantity (volume, concentration) of biological agent must be present. Even a small amount of an agent could result in severe consequences, such as a laboratory-associated infection. Furthermore, exposure to larger quantities of that agent (greater than the infectious dose) may result in a more severe presentation of the infection. High communicability Even one single exposure (causing carriage or a laboratory-associated infection) could rapidly spread from laboratory personnel or fomites to many individuals. High severity and mortality A laboratory-associated infection following exposure is more likely to cause personnel to become debilitated, lose their quality of life or die. Limited availability of effective prophylaxis The symptoms or outcomes of a laboratory- or therapeutic interventions associated infection cannot be effectively prevented, reduced or eliminated by a medical intervention. This may also include situations where medical intervention is not available, or emergency response capacity is limited. Large susceptible population (including The larger the susceptible population, the laboratory personnel at increased risk) more likely a laboratory-associated infection could rapidly spread and infect larger numbers of people. Lack of endemicity (such as exotic disease) When an agent is not endemic in the surrounding population, the population is more likely to be susceptible to the agent, leading to an increased likelihood of a laboratory-associated infection spreading to the community.  SECTION 2 RISK ASSESSMENT 15 Table 2.4 Factors associated with both a high likelihood of and greater consequences from a potential incident FACTORS ASSOCIATED WITH BOTH A RATIONALE HIGH LIKELIHOOD OF AND GREATER CONSEQUENCES FROM A POTENTIAL INCIDENT HIGHER LIKELIHOOD AND GREATER CONSEQUENCE High concentration or volume of the The more biological agent there is in the biological agent substance being handled, the more infectious particles there will be available for exposure, and the more likely the exposure volume will contain the infectious dose of that agent. Furthermore, being exposed to a higher concentration of the agent could result in a more severe infection, illness or injury. Airborne route of transmission Biological agents with an airborne route of transmission may be capable of remaining airborne in aerosols for prolonged periods of time and may disseminate widely in the laboratory environment, increasing the likelihood that personnel may be exposed to the agent. Furthermore, following an exposure event, aerosolized biological agents may be inhaled and deposit on the respiratory tract mucosa of the exposed individual, possibly leading to a laboratory-associated infection. 2.2.2 Determine the initial risk The information gathered must then be used to establish how much risk a particular situation presents (for example, how likely and how severe). Table 2.5 shows a risk assessment matrix which provides a simplified example of how to assess the relationship between likelihood and consequence in order to determine the initial risk of exposure to and/or release of a biological agent. In reality, the relationship comparison may include a broader or more complex range of values for determining likelihood and consequence than that which is shown in Table 2.5, but it is a useful tool to demonstrate how the initial risk can change relative to these independent factors. In addition to the method described here, there are further methods to determine initial risk and prioritize risks for the implementation of risk control measures. Institutions should employ a risk prioritization strategy that best meets their unique needs while acknowledging the limitations of the selected strategy and ensuring that professional judgement remains a critical part of the risk prioritization process. 16 LABORATORY BIOSAFETY MANUAL – FOURTH EDITION Table 2.5 Risk assessment matrix Severe Medium High Very high Consequences of exposure / Moderate Low Medium High release Negligible Very low Low Medium Unlikely Possible Likely Likelihood of exposure/release 2.2.3 Establish an acceptable risk Once the initial risk has been evaluated, it is necessary to determine whether this risk is acceptable to allow work to proceed. If it is not, a risk control strategy will be required to reduce and sustainably control those risks appropriately as described in the next step of the risk assessment framework. It is important to acknowledge that there will never be zero risk, unless the work is not conducted at all, so a balance must be carefully managed between conducting the work and ensuring that personnel and the community are as safe as possible from inadvertent exposure to and/or release of biological agents. It is also important to recognize that the work being performed in the laboratory offers considerable benefits to both health care and global health security that justifies a certain degree of risk. Determining the acceptable risk is essential in providing a benchmark below which the initial risk must be reduced in order for work to be considered safe enough to proceed. It is important to note that risk can never be completely eliminated unless the work is not performed at all. Therefore, determining if the initial and/or residual risks are acceptable, controllable or unacceptable is a vital part of the risk evaluation process. Beyond what is regulated by national legislation and policies (27), the acceptable risk must be established by an organization itself so that it is proportionate to the organization’s situation and resources. Consideration must be given to organizational risks such as compliance risk (legal action, fines, citations), security risk (theft or loss), environmental risk (socioeconomic impact on community health and agriculture), and even perceived risk (subjective judgements or uncertainty about the severity of risk). Perceived risks of the personnel should be taken seriously. Self-introduced risk control measures by the personnel should be avoided.  SECTION 2 RISK ASSESSMENT 17 Taking into consideration the risk perceptions of relevant stakeholders (for example, government departments, donors, audit/oversight agencies, the general public and the local community), especially where high actual risks are involved, may be useful to allay the fears of those stakeholders who might otherwise be resistant (for example, politically or administratively) to the laboratory performing its usual functions. 2.3 Develop a risk control strategy Once an acceptable risk has been established, a risk control strategy must be developed to reduce any initial risks to an acceptable risk and allow the work to proceed safely. As previously mentioned, because elimination of risk is not generally possible in practice, careful selection of a risk control strategy is required to ensure that risks are prioritized against the available resources with the understanding that a low acceptable risk will require many more resources to implement and maintain the relevant risk control measures needed to reduce the risk. Acceptable risk, however, must not be raised unnecessarily as a substitute for making resources available to fulfil the necessary risk control strategy and provide the appropriate protection. Resources must be made available or work should not proceed. There are a number of different strategies that may be used to reduce and control risks. Often, more than one risk control strategy may need to be applied in order to reduce the risks effectively. Table 2.6 provides an overview of some of the most common strategies employed for risk control and examples of the risk control measures. A good risk control strategy will: n provide an overall direction of the nature of the risk control measures that may be required to reduce unacceptable risks, without stipulating necessarily the types of risk control measures that can be used to achieve this reduction, n be achievable using the available resources in the context of the local conditions, n help minimize any resistance to the work being performed (for example, addresses the risk perceptions of relevant stakeholders) and secure support (for example, approvals from national/international regulatory authorities), n align with the overall goals, objectives and mission of the organization and facilitate success (that is improves public health and/or health security). 18 LABORATORY BIOSAFETY MANUAL – FOURTH EDITION Table 2.6 Strategies for risk reduction STRATEGY EXAMPLE Elimination Eliminate the hazard: § use an inactivated biological agent, § use a harmless surrogate. Reduction and substitution Reduce the risk: § substitute with an attenuated or less infectious biological agent, § reduce the volume/titre being used, § change the procedure for one that is less hazardous, such as polymerase chain reaction rather than culture. Isolation Isolate the hazard: § elimination and reduction might not be possible, particularly in a clinical setting, therefore isolate the biological agent(s) (for example, in a primary containment device). Protection Protect personnel/the environment: § use engineering controls (for example, BSC), § use PPE, § vaccinate personnel. Compliance Have administrative controls and effective biosafety programme management in place such as: § GMPP observed by personnel, § good communication of hazards, risks and risk control measures, § appropriate training, § clear SOPs, § an established safety culture. BSC = biological safety cabinet; GMPP = good microbiological practice and procedure; PPE = personal protective equipment; SOPs = standard operating procedures. 2.4 Select and implement risk control measures Once a risk control strategy has been developed, risk control measures must be selected and then implemented in order to fulfil the risk control strategy. In some cases, the nature of the risk control measures required will be predetermined, prescribed by a set of minimum standards for risk control (for example, by internationally accepted best practice, national/international regulations). However, for some cases, a variety of risk control measures will be available to appropriately achieve the risk control strategy depending upon the nature of the risk identified, the available resources, and other local conditions.  SECTION 2 RISK ASSESSMENT 19 It must be remembered that even after a risk control measure is selected for your risk strategy, a certain degree of risk will still remain. If that risk, known as the residual risk, is still unacceptable, additional and/or more effective risk control measures may need to be used to fulfil the risk control strategy and bring the risk to an acceptable risk. Usually, the higher the initial risk, the greater the number of risk control measures needed to reduce the residual risk to an acceptable risk for work to continue. However, the relative effectiveness of each available risk control measure to reduce the evaluated risks will also affect how many risk control measures are needed to close the gap between the residual risk and the acceptable risk. Furthermore, the use of multiple risk control measures in combination to reduce the residual risk may have further benefits in building redundancy in case of failure of one or more of the selected risk control measures. The following subsections provide an overview of the key considerations required for the selection and implementation of risk control measures in order to fulfil the risk control strategy. 2.4.1 Select risk control measures When selecting laboratory risk control measures, national regulations and guidelines must always be considered first to ensure compliance. These may be verified through inspections, certifications, audits and assessments, and be overseen by nationally appointed authorities. The remainder of this subsection describes the selection of risk control measures at the laboratory level, outside those required by any national regulations that may be in place. For most laboratory activities, the likelihood of exposure and/or release is unlikely, with a negligible to moderate severity of consequences. This means the initial risk is very low or low and is often near or below the acceptable risk even before risk control measures are applied. International guidance and accepted best practice for biosafety recommend the adoption of a basic set of biosafety principles, technologies and practices to act as risk control measures to ensure that all work remains below the accepted risk. For this reason, this manual provides a minimum set of risk control measures to be implemented during any work with biological agents. This combination of risk control measures is known collectively as the core requirements and include tools, training, and physical and operational controls considered necessary to work safely in most laboratory situations. These requirements are described in more detail in section 3 core requirements. However, it is important to note that despite the low risk, GMPP still needs to be promoted and laboratory activities needs to be reviewed periodically to ensure that GMPP and all the core requirements are effectively implemented to complete the risk assessment framework. The majority of clinical and diagnostic laboratory work will require only the prescribed core requirements to effectively control risks. 20 LABORATORY BIOSAFETY MANUAL – FOURTH EDITION For cases where initial risks fall into higher categories, a selection of additional risk control measures will be required in addition to the core requirements. Examples of factors associated with a likely or possible likelihood of and/or severe consequence of an incident occurring are shown in Tables 2.2 to 2.4. Under such circumstances, the additional risk control measures selected to reduce the residual risk to an acceptable risk are considered heightened control measures. Biological agents and procedures that require heightened control measures may vary, ranging from culture and propagation of biological agents in small volumes with a medium risk to large-scale work with drug-resistant strains or animal studies with aerosol-transmissible, zoonotic agents, which are considered high risk. The heightened control measures should be appropriate and proportionate to address the specific factor(s) that contributes to the likelihood and/or consequence of an exposure and/ or release; for example, a procedure with an aerosol risk should have a risk control measure that is effective at capturing aerosols. For this reason, the most appropriate heightened control measure will also vary considerably depending on the biological agents being handled, procedures being performed and potential transmission routes. All heightened control measures will have advantages and disadvantages that must be carefully considered when selecting the appropriate ones to close the gap between the residual risk and the acceptable risk. Where the evaluated risks are considered high on the risk spectrum, cost–benefit analyses should be undertaken to assess options such as outsourcing the work (to a suitable facility that has the appropriate risk control measures and resources in place), as well as a detailed evaluation of heightened control measures that could be implemented to enhance the laboratory facility. The risk control measures chosen will be most effective when they are selected to meet local needs. It is important to note that while a hierarchy of risk control measures has been defined by many countries, it cannot be assumed that one risk control measure is always preferable to another (such as engineering controls versus personal protective equipment). Usually, heightened control measures should be selected based on available evidence of their effectiveness, either through peer-reviewed studies or other reliable sources of information. Where reliable information does not exist, in-house validation of risk control measures may be required. Where applicable, publishing in-house validation in peer-reviewed journals should be considered so that others can benefit from the conclusions of such studies. This includes new information, previous incidents and the effectiveness of and the protection afforded by the risk control measures. Such studies may also help highlight the likelihood of exposure associated with specific equipment or procedures, which can be included in future information-gathering activities and be used to inform the risk evaluation step in the risk assessment framework.  SECTION 2 RISK ASSESSMENT 21 Some of the most commonly used heightened control measures are discussed in more detail in section 4 heightened control measures, including their relative effectiveness when used in different local conditions. Where heightened control measures are applied, it is important to recalculate the residual risk after a risk control measure is selected and estimate whether this has effectively brought the residual risk to the acceptable risk. This requires a re-evaluation of the residual risk, guided by questions such as: n Has the possibility of an exposure/release become less likely to happen? n Have the consequences become less severe? n Have the likelihood and consequences been reduced such that the residual risk is acceptable? n If no, are additional risk control measures available? n Should work proceed, with or without which risk control measures? n Who has the authority to accept the residual risk and approve the work to go ahead? n How should the selected risk control measures and subsequent approval for work to proceed be documented? In very rare situations, there may be a very high likelihood of exposure and/or release. However, more important is the possibility of severe consequences from any exposure and/or release if it were to occur. Such cases include work with globally eradicated pathogens, or with highly transmissible animal pathogens that could spread rapidly in susceptible populations upon release and cause widespread panic, and decimation of species and/or livelihoods. The risk would be further increased if the agent were propagated in liquid media, particularly if in large volumes, and if infectious aerosols were produced (for example, in vaccine development studies). In such cases, a very high initial risk of exposure to and/or release of a biological agent exists which will likely require a highly specialized, highly effective set of risk control measures to reach an acceptable risk, if the work is to be performed at all. This includes a large set of strict and complicated operational practices, safety equipment and facility design criteria which can be referred to as maximum containment measures; these are described in more detail in section 5 maximum containment measures. As maximum containment measures are necessary to provide the highest protection against the most severe consequences of an exposure or release, evaluating the feasibility of effectively implementing and maintaining maximum containment measures is an extremely important and necessary exercise. This would require frequent and rigorous verification of procedures, equipment and laboratory facilities. Periodic review must also include analysis of ongoing studies to ensure they are adequately justified with the scientific benefits outweighing the biosafety risks. 22 LABORATORY BIOSAFETY MANUAL – FOURTH EDITION While an overview of the commonly employed maximum containment measures are presented in this manual, the specialized and complex facilities and expertise required to implement maximum containment measures are only available in a very few laboratories worldwide. Implementing risk control measures of this complexity requires careful individual consideration by experienced international experts as well as coordination by many sectors, normally including government. For this reason, it is not possible to provide a specific set of requirements applicable to each situation that is considered to require maximum containment measures. The following schematic (Figure 2.2) summarizes the risk outlined in Table 2.5 (the risk assessment matrix) and associates the risks with the types of risk control measures likely to be required. It highlights the following: n Most laboratory activities can be safely executed using core requirements, where the risks are very low to low, n Some laboratory activities will require heightened control measures to safely control the associated risks, which may be medium to high, and n A very small amount of laboratory work will require maximum containment measures due to very high risks, particularly those risks associated with catastrophic consequences. 2.4.2 Implement risk control measures Once the appropriate combination of risk control measures has been selected, necessary approvals should be obtained. A proper review of cost, availability of funding, installation, maintenance, and security and safety criteria should be undertaken to ensure that the risk control measure(s) can be effectively used as part of the risk control strategy and can be sustained by the available laboratory resources. Each person operating laboratory equipment must be trained on the correct operating procedures required for each and every risk control measure in the laboratory, which may require SOPs to be written or updated. Consideration should also be given to ensuring that the risk control measures selected will not introduce their own risks to the work. For example, multiple layers of PPE might increase the likelihood of mistakes occurring because of reduced dexterity or increase the likelihood of contamination if it is difficult to remove, thereby increasing the overall risk of exposure. Non-biological risk factors of the selected risk control measures should also be considered; for example, specialized design features of furniture or equipment should not introduce ergonomic problems for personnel.  SECTION 2 RISK ASSESSMENT 23 Severe Maximum Heightened control measures containment measures Moderate Consequence of exposure or release Core requirements Negligible Unlikely Possible Likely Likelihood of exposure or release Figure 2.2 Risk control measures needed based on the likelihood and consequence of exposure or release Finally, once risk control measures have been selected, approved and acquired, information about their purpose, function and use must be communicated to all applicable personnel if they are to be implemented correctly and be effective. Communication is a vital part of biosafety and risk assessment. Without it, it is unlikely that the risk control measures will reduce residual risk. All those working in the laboratory are responsible for following the appropriate practices and procedures of any risk reduction strategy that applies to them and for providing feedback on their effectiveness. To achieve the appropriate level of awareness, training and competency for implementation of risk control measures and safe laboratory operation requires, at a minimum, communication of the hazards (biological agents) present, communication of the risks associated with the procedures being performed and communication of exactly how the risk control measures used can most effectively reduce those risks. Strategies for communication and outreach beyond traditional biosafety training include laboratory-specific SOPs, interactive team discussions, job aids and posters, generic awareness-raising through short publications (for example, pamphlets, handouts), briefings and email notifications. 24 LABORATORY BIOSAFETY MANUAL – FOURTH EDITION Table 2.7 provides some basic examples of laboratory activities and shows how the application of risk control measures affects the residual risk. Table 2.7 Examples of laboratory activities, their initial risk, and residual risk after application of appropriate risk control measures PROCEDURE INITIAL RISK RISK CONTROL RESIDUAL RISK (LIKELIHOOD/ MEASURE(S) CONSEQUENCE) Polymerase chain Very low (Unlikely/ CR Very low reaction analysis of Negligible) inactivated sputum specimen Smear preparation Low (Unlikely/ CR Very low and microscopy of Moderate) sputum specimen Culture on solid Medium (Possible/ HCM (for example, CR Low media for antibiotic Moderate) plus respiratory sensitivity testing protective equipment) Culture in small High (Likely/ HCM (for example, CR Low/Medium quantities Moderate) plus biological (< 50 mL) for strain safety cabinet) characterization including antibiotic resistant strains Culture in large High (Possible/ HCM (for example, CR Medium quantities (> 10 L) Severe) plus biological for animal challenge safety cabinet and study via aerosol respiratory protective route equipment) Biological agent Very high (Likely/ MCM Medium has been globally Severe) eradicated with studies ongoing with above procedures CR = Core requirements; HCM = Heightened control measures; MCM = Maximum containment measures. Note: Unless otherwise noted, the biological agent considered in the above scenarios has a low infectious dose, is transmitted via aerosol route and is susceptible to available treatments.  SECTION 2 RISK ASSESSMENT 25 The goal of risk communication is to help all stakeholders, including laboratory personnel, involved in the implementation of risk reduction strategies to understand the risk assessment method(s), results and risk control measure decisions. Risk communication is vital to allow laboratory personnel to make informed choices about how to perform their role in the laboratory and to establish a successful safety culture built around effective risk-reduction strategies. Furthermore, strong communication practices will help establish good reporting mechanisms for any incidents, accidents or inefficiencies of the risk control measures. Risk communication also plays an important role in the laboratory’s relationship with outside stakeholders, such as regulatory authorities and the general public. Maintaining open communication lines will also be beneficial when conducting future assessments. Written documents are essential to maintain an accurate and historical record of risk assessments and communicating the results to laboratory personnel. 2.5 Review risks and risk control measures Once performed, risk assessments must be reviewed routinely and revised when necessary, taking into consideration new information about the biological agent, changes in laboratory activities or equipment and new risk control measures that may need to be applied. Suitable procedures must be put in place not only to ensure implementation and reliability of the risk control measures, but also to ensure that they are sustainable. Confirmation that measures are effective and that training has been carried out appropriately can be verified through inspection, review and audit of processes and documentation. This will also provide an opportunity for improvements to be made to the processes and associated safeguards. This will include a careful review of laboratory-associated infections, incidents, accidents as well as literature reviews and relevant references. As was indicated for the initial risk