BSL-2 Language Urban Legends
Urban Legends: BSL2+, BSL2E, BSL3+, & BSL3E Don’t Exist.
“Biological safety cabinets [Biosafety Cabinets] (BSCs), splash shields, and other physical containment devices must be available for the manipulation of infectious agents when procedures likely to generate aerosols and splashes are conducted. Filtered exhaust air from BSCs can either be recirculated into the laboratory space or can be vented into dedicated plenums.” [emphasis mine].
They do use the dreaded term “enhanced” in the document as follows:
“BSL-2 laboratories that do not have a BSL-3 facility should utilize enhanced BSL-2 practices and take extra precautions when working with a potential high-risk pathogen.”
The meaning of what “enhanced BSL-2 practices” and “extra precautions” mean is not defined.
• This is an interesting discussion, I found this very confusing on what entails BLS2+ (CL2+ in our facilities) or enhanced CL2 practices so I consistently use CL2 with CL3 operational practices (CL3 ops). It may feel a bit long but higher containment practices are needed based on local risk assessment.
• I’m also confused when lab design (P) is mixed with lab practices and agent risk groups. In my opinion, risk analysis of research should consider facility design, agent risk group, and practices/procedures. BSL-E is not the way to go.
• Show me where that definition is spelled out in any regulatory document? It seems to me that we use that term, but what we are really talking about is BSL2 or BSL3 with added precautions based on the risk assessment. Therefore, the term “+” is really a conglomeration of numerous additions which are not all necessary for every specific condition. Why don’t we call it what it is: BSL2 or 3 and be specific about what we added based on the needs identified by the risk assessment for the project?
• Answer: There is no definition. Don’t use the terms.
• In my opinion, the terms Biosafety Level -Plus and -Enhanced do not exist in biosafety guidelines because the terms are meaningless.
• When an organization is using these terms, they must define what design change they have made that prompted them to use -Plus or -Enhanced terminology. For example, researchers may designate their lab BSL-2 Enhanced because their laboratory sink drains are directly connected to a disinfection system. The range of modifications is endless!
The engineers stated that when clinical laboratories do not have access to a BSL-3 facility, their work may be conducted safely at Biosafety Level 2 Plus (BSL-2+) containment with BSL-3 practices and procedures.
• Biosafety Levels (BSL-1, 2, 3, and 4) describe the physical design of laboratories and equipment associated with each level. Biosafety Levels are not synonymous with organism risk groups RG 1, 2, 3, and 4. Biosafety Levels are also not synonymous with specific types of personal protective equipment and practices.
• Biosafety Level 2 Plus (BSL-2+) is the common term for laboratories where work with microorganisms is conducted in a BSL-2 laboratory with biosafety practices and procedures that are typically found at BSL-3. The need for this hybrid approach is on the rise in recent years due to increased research with viral vectors, arboviruses, and other emerging infectious diseases.
• But implementation can be challenging since it is not a recognized containment level, so no clear prescription for implementation is available. Most research institutions that could benefit from this hybrid approach struggle to determine when it is safe and appropriate to use it and which BSL-3 practices to use. BSL-2+ is not a recognized containment level in biosafety guidance documents such as the Centers for Disease Control and Prevention’s (CDC) Biosafety in Microbiological and Biomedical Laboratories (BMBL) or the National Institutes of Health’s (NIH) Guidelines for Recombinant and Synthetic Nucleic Acid Molecules.
• Other biosafety guidance documents such as the NIH’s Biosafety Considerations for Research with Lentiviral Vectors refer to “enhanced BL2 containment” (another term for BSL-2+) but do not detail how to implement it. It is important to know that BSL-2+ is not appropriate for pathogens that are infectious via the inhalation route in the research setting. At a minimum, such pathogens must be utilized in a BSL-3 laboratory with BSL-3 practices. Clinical laboratories have different needs and challenges, for more on this you can read our post, Clinical Laboratories: Using BSL-2 Plus When Working with Pathogens Transmitted via Inhalation. To determine if your research can be safely conducted in a BSL-2+ environment, you must conduct a risk assessment.
• Critical First Step: Conducting a Risk Assessment to Identify Biosafety Level and Practices. BSL-2+ is used when a pathogen is determined to require BSL-2 physical containment using safety practices over and above the practices required at BSL-2.
• There is no standardized list of microorganisms, viral vectors or research projects that should be conducted at BSL-2+. To determine if BSL-2+ is suitable for your research you must first conduct a risk assessment in accordance with the process defined in the BMBL. The risk assessment guides the selection of appropriate biosafety levels and microbiological practices, safety equipment, and facility safeguards that will contribute to preventing a laboratory exposure. As outlined in the BMBL, the steps of the risk assessment process include: Identify agent hazards and perform an initial assessment of risk. Identify laboratory procedure hazards.
• Decide the appropriate biosafety level and select additional precautions as indicated by the risk assessment. Evaluate the proficiencies of staff regarding safe practices and the integrity of safety equipment. Review the risk assessment with a biosafety professional, subject matter expert, and the Institutional Biosafety Committee (IBC). The risk assessment process must be conducted for every new or revised research project.
• Examples of when BSL-2+ may be appropriated include: Viral vectors with gene inserts consisting of oncogenes or genes of unknown function. Second generation lentiviral vectors which have an increased risk in recombination to generating replication-competent lentiviruses. Drug resistant Risk Group Two (RG2) bacteria such as methicillin resistant Staphylococcus aureus (MRSA). RG2 organisms with low infectious doses which can cause serious disease (e.g., Salmonella Typhi, Shigella). Organisms where certain factors predispose individuals to infection or negative health outcomes (e.g., Zika, Listeria monocytogenes). Low titer and small volumes of Human Immunodeficiency Virus (HIV), an RG3 agent. High concentrations (>106 PFU/mL) of RG2 viruses. Work with greater than 10 liters of a RG2 agent. Organisms that present certain biocontainment and/or biosecurity concerns (e.g., low pathogenic avian influenza). Project Review Process.
• The project review process is part of the risk assessment and includes these steps that must be completed before work can be approved and begin: Submission of a project registration document by the Principal Investigator (PI) to the Biosafety Officer (BSO). Define the project purpose and document the steps to be conducted with the biohazardous material. Review and discussion of the project registration document with the PI, BSO and in some cases selected members of the IBC. An IBC and adherence to the NIH Guidelines are mandatory if the institution receives federal funding and/or is located in a community with a recombinant DNA ordinance.
• If your institution does not require an IBC, then a similar type of review committee such as a Biosafety Committee should be part of the review process. If the review process determines that a BSL-3 containment facility is not necessary, but BSL-2 practices may not provide adequate safeguards, then the use of BSL-3 practices in a BSL-2 laboratory may be appropriate. At this point a suitable BSL-2 laboratory space should be recommended (we’ll cover selecting a space in the next section) and the BSL-3 practices to be used outlined.
• Prior to initiation of the project the IBC members should come to consensus on the appropriate BSL-3 practices that should be applied to the proposed work. And at this stage, a suitable BSL-2 laboratory space should be agreed upon. Risk communication and training must be conducted after IBC approval and before any work is performed. The BSO should review the required BSL-3 procedures with the PI and laboratory staff. Ideally these should be documented in the form of a Standard Operating Procedure (SOP). Review the laboratory space to ensure the required BSL-2 elements are in place such as biowaste containers, sink with soap and paper towels, and certified biological safety cabinets (BSCs).
• Selecting a Laboratory Space for BSL-2+. Often academic and research BSL-2 laboratories are large spaces occupied by many lab personnel working on a variety of projects and sharing lab equipment. In some cases, this may not be conducive to adhering to BSL-3 practices. For this reason, a separate BSL-2 laboratory space may need to be dedicated to the project that requires BSL-3 practices. Practically speaking this usually means taking a smaller BSL-2 or “tissue culture” laboratory room and dedicating it to the project. This allows access to be limited to only those people who have received the necessary training and are listed on the research protocol. Selecting and Modifying BSL-3 Practices. It is important to keep in mind the BSL-3 requirements for work practices and safety equipment such as personal protective equipment (PPE) and BSCs.
• Sometimes the appropriate BSL-3 practices determined by the risk assessment may be limited to restricting sharps in the laboratory. In other situations, multiple BSL-3 practices are selected. Each risk assessment and project review should include a review of these practices and equipment requirements to determine the items that will protect workers and the surrounding community. Each item may be subject to discussion and there is room for adjustments, provided there is consensus among the IBC members.
• Other Issues to Consider When Implementing BSL-2+ Practices. Often there are other issues that should be given careful consideration and reviewed such as: If the BSL-2+ laboratory has adequate space to accommodate additional research projects, you will need to decide whether to allow other lab personnel to work in the space with materials of a lesser hazard. If the project approved with BSL-3 practices involves work that occurs infrequently, you may need to decide whether to revert the lab back to a standard BSL-2 lab with BSL-2 practices. Consider the materials in use and whether the lab and equipment should be decontaminated prior to downgrading. Signage would also need to be updated. If this practice is allowed, you will need to develop an SOP detailing the process and provide training. Is it appropriate for lab personnel to bring notebooks and portable electronic devices in and out of the BSL-2+ lab? Best practice is to prohibit this in order to avoid bringing contamination out of the lab but provide other methods for information to be transmitted to the office area through a fax machine or a computer that is dedicated to the BSL-2+ lab.
• If the BSL-2 laboratory will be renovated or built for a project using BSL-3 practices, you may find it useful to incorporate some of the BSL-3 lab facility requirements. For example, a hands-free or automatically operated sink for hand washing may be worthwhile. Or, installing an anteroom between the lab and external areas may be useful for storage of PPE. If the BSL-2 laboratory is an animal biosafety level two (ABSL-2) facility, then animal biosafety practices, procedures and safety equipment criteria must be incorporated. The risk assessment guides the decision as to what ABSL-3 practices to incorporate. The use of BSL-3 practices in a BSL-2 laboratory may be appropriate for some research projects and may contribute to the safe conduct of that research. Since there is no “one size fits all” approach, the risk assessment is key to determining whether BSL-3 practices are appropriate in a BSL-2 lab facility and what practices will be required. Strong collaboration between the PI, BSO, IBC and lab personnel is also crucial to the successful outcome. For more information on implementing a BSL-2+, download our guide that includes illustrative case studies. A Practical Guide to Implementing a BSL-2+ Biosafety Program in Research Laboratories
• While BSL-2 + is often and unfortunately used the correct terminology is BSL-2 enhanced.
• High Containment project is about BSL3 ,ABSL 3 Ag and BSL4. Not existing BSL2 +or BSL3 +
• Before the early 1980’s biological research lab design designations were P-1, P-2, P-3, and P-4. Yes, “P” meant Physical -from the 1976 NIH Guidelines for Recombinant DNA Research. The first draft BMBL circulated in March 1983 for review and comment by September 1983 to Dr W Emmett Barkley, Director, Division of Safety, NIH, changed “P” to Biosafety Level “BSL-1-4”.
• Colleagues, just to chime in as a long time (geezer) clinical microbiologist, the issue seems to be that some smaller microbiology laboratories still do not have biosafety cabinets in their sample processing areas.
• It seems past time that CLIA regulations require them. To my way of thinking, any clinical laboratory that does not use one (based on risk assessment of the pathogens likely to be encountered in their region) is not adequately protecting their workers. If primary specimens are manipulated only in certified Class II BSCs, with rigorous application of good laboratory practices for handling cultures that contain agents requiring respiratory precautions, there is little need for any other “enhancements”.
• All other “enhancements” to BSL-2 practices or facilities such as unidirectional airflow will not significantly increase safety. A small clinical laboratory in central Missouri might occasionally process samples from patients with suspected tularemia or TB but these can all be safely handled by following ASM and APHL sentinel laboratory guidelines. We MUST stop promulgating the myth that “enhanced” BSL-2 is a real thing.
• Totally agree with you & not because we both worked at BD. As a former clinical microbiology postdoc with Frank E Young, former Commissioner of Food & Drugs, the DX labs do just fine, without making up enhanced lab design – should we return to P-1 to P-4? Canada has different lab design designations!
• Defining BSL-2+ and BSL-2E are in the eye of the beholder as you describe.
• Often people use the terms to describe the lab design (BSL-2) plus use of non-laboratory specific PPE/Practices.
• Before the early 1980’s biological research lab design designations were P-1, P-2, P-3, and P-4. Yes, “P” meant Physical -from the 1976 NIH Guidelines for Recombinant DNA Research. Clearly referring to the design of the physical laboratory.
• Maybe the issues arose when there was a blending of practices and facility design when the term “Biosafety Level” began with the first draft BMBL.
• The draft BMBL was circulated to established biosafety individuals in March 1983. Reviews and comments were to be returned by September 1983 to Dr W Emmett Barkley, Director, Division of Safety, NIH. The first edition of the BMBL, edited by John H. Richardson, D.V.M, M.P.H. and W. Emmett Barkley, Ph.D., was published in March 1984.
• The BMBL 1st Edition states – “The descriptions of biosafety levels 1-4 parallel those of P1-4 in the NIH Guidelines for Research Involving Recombinant DNA and are consistent with the general criteria used in assigning agents to Classes 1-4 in Classification of Etiologic Agents on the Basis of Hazard. Four biosafety levels are also described for infectious disease activities utilizing small laboratory animals. Recommendations for biosafety levels for specific agents are made on the basis of the potential hazard of the agent and of the laboratory function or activity.” — Thus, the last sentence describes the mixing of laboratory design (P) and Cl (now RG) activities under the term “Biosafety Level”.
• It is not that BSL-2 enhanced or + is not real, it is just that there is no agency that is defining it. At M.I.T., Wyeth and Pfizer, all places that I worked, we used BSL-2+ (M.I.T.) or at the biopharma’s – enhanced. BSL-2+ was an agreed upon standard within the City of Cambridge. At the biopharma’s, it was a companywide definition. In both places it filled the need to define a lab that was operating above the baseline BSL-2 facility. BSL-2+ in Cambridge at that time, meant a level 2 facility with level 3 personnel practices. At Wyeth/Pfizer it was flexible as to what was added depending upon a risk assessment. While it is not universally meaningful, it has meaning in the institutions using that designation and it was a lot easier to make a sign with “BSL-2+” or “BSL-2E” then “BSL-2, all work with live organisms must be performed in a BSC” .
• This “Define BSL2+/Enhanced or BSL3+/Enhanced” thread started for me when I responded to a blog on Twitter, February 1st from an engineering consulting firm that was stating that when clinical laboratories do not have access to a BSL-3 facility, their work may be conducted safely at Biosafety Level 2 Plus (BSL-2+) facility. I responded by asking where BSL-2+ is defined – it isn’t).
• I agree that the Canada Containment Level (CL) for laboratory design separates RGs and BSL-3 microorganisms.
• The WHO Laboratory Biosafety Manual 4th Edition will be out soon and may help settle the issue.
• Yes, I was disappointed to see the use of BSL-2 enhanced term for labs that don’t have BSL-3 facilities in the Interim Clinical Laboratory Guideline for Biological Safety. The guideline also uses the term “Biological Safety Cabinet” which was changed to “Biosafety Cabinet” many years ago by NSF International in the NSF/ANSI Standard 49 Biosafety Cabinetry.
• I have a Frank’s lab memory lane item for you. I joined Frank’s lab in Rochester just after he moved his lab from Scripps, La Jolla. Gary Wilson and other postdocs that moved with him were not happy! Speaking of physical containment; the EB virus lab next to my lab at the Philadelphia medical school split TC’s in a closet with a built-in table and a chair (no BSC).
• I prefer the Containment Level designation that the Canadians have adopted. Use of CL helps people understand that the laboratory design criteria are distinct from risk groups for organisms, unlike the problem of some erroneously referring to pathogens as “BSL-3 bugs”.