Mar 01, 2021 | 4 min read
Last November, the Centers for Disease Control (CDC) published the sixth edition of Biosafety in Microbiology and Biomedical Laboratories (BMBL). The book—considered by many to be the gold standard for good laboratory biosafety practices—was first released in 1984. Though the information within is intended as guidance and not necessarily regulation, many laboratories use it as more than an advisory document. The latest version contains several changes that are useful to clinical laboratories.
Greater emphasis on risk assessments
Since its inception, the BMBL has been rooted in the concept of protocol-driven risk assessments. Edits have been necessary in order to keep the document current with the biosafety issues of recent years and to link the assessments with ongoing safety practices.
Risk assessments are now considered by the authors to be part of a continuing risk management process in the laboratory. No longer should they be performed and put aside, as some labs have done in the past. This ongoing risk management review should play a key role improving the overall lab safety culture.
In addition to changes in the overall risk assessment focus, individual sections of the BMBL6 were also upgraded. The section on occupational health support was revamped to better discuss how integral the occupational health provider is to the lab safety process, and elements of risk assessment practices were added here as well. The provider has the role of alleviating the risk of adverse health consequences due to potential exposures to biohazards in the laboratory. This updated section provides a framework for what the occupational health support should include and reviews the regulatory requirements for such programs. The new risk-based occupational health section introduces the use of Risk of Exposure (RoE) and Risk of Disease (RoD) for post-exposure assessments, which can help the occupational health program document lessons learned from exposure incidents, thereby decreasing the chances for future exposures. The use of these new factors can help labs navigate how to proceed when accidental agent exposures occur.
The need for biosafety manuals
The biosafety level sections of the BMBL6 contain information about the need for a written biosafety manual. The lab manual needs to be specific to the facility, and it must be approved by the laboratory medical director in concert with lab safety professionals. This set of biosafety references should be available to staff at all times and updated or reviewed regularly. The purpose of this manual is to provide information to lab staff about containment procedures for the biological materials handled, agent-handling procedures, and information about decontamination. The biosafety manual should also provide guidance for emergency situations like exposures, injuries, and other possible lab accidents. Staff should be trained and ready to handle such situations when they arise.
Potentially dangerous agents
The authors updated the agent summary statements to include the most current information about the dangerous agents handled in many laboratories. New hazard mitigation strategies have been introduced where applicable, and detailed information is provided for the safe handling of select agents. The viral agents section contains updated information about SARS-CoV and MERS viruses, both of which have recently had significant roles on the world stage. The information includes a history of occupational infections, natural modes of infection, and laboratory safety recommendations.
The newly added Appendix K, Inactivation and Verification, discusses the vital topic of ensuring that agents used in the laboratory are chemically or physically inactivated, and that staff can verify or prove inactivation. This section provides detailed information regarding how laboratories are to be in compliance with current agent inactivation regulations from the Federal Select Agent Program. The authors describe agent inactivation procedures (physical, chemical, and natural) and the advantages and disadvantages of each. They also provide validation processes to ensure that labs have rendered the pathogen or toxin inert.
Appendix N, Clinical Laboratories, is another new section that delivers guidance for laboratorians in the framework of the long-utilized hierarchy of controls. When discussing administrative controls, the appendix introduces the idea of “trigger points” in lab processes, where high-risk activities or potential pathogens can be identified. Lab safety training should help staff recognize certain triggers, which would prompt them to utilize additional safety measures. For example, bacterial growth from a cerebrospinal fluid (CSF) sample should trigger the worker to conduct any further workup inside of a biosafety cabinet for better protection. The appendix reiterates that clinical samples may contain unknown pathogens, and all specimens should be treated as if infectious. Clinical laboratory emergency management procedures are highlighted in this section as well.
Other important additions
Appendix L, Sustainability, discusses how laboratories can utilize processes that save water, energy, and that can reduce departmental waste. The information provided can be used by new labs or labs planning to undergo renovations.
Appendix M, Large Scale Biosafety, offers special considerations for laboratories that work with biological agents in large-scale quantities. The risk management focus is changed when working with larger equipment or higher volumes of chemicals and raw materials, and the appendix provides details on engineering controls for labs in those situations.
The BMBL has for many years been the go-to source for information about laboratory biosafety levels one through four, and what the requirements are for each. The new guidance adds some updated biosafety levelspecific recommendations and features. For example, it now discusses a method for communication in and out of the lab for BSL3 and BSL4 spaces. It also includes new requirements for BSL3 and BSL4 labs that include testing of the spaces to ensure the safety operational parameters are met after significant renovations, or at least annually. And the book now includes guidance for adequate lab lighting for all biosafety levels.
A key resource for the lab
The BMBL can be either purchased as a hard copy or downloaded from the CDC website for no cost. This free resource has been used for decades because it provides lab biosafety information that is considered best practice for laboratories everywhere. The sixth edition represents intensive work by a team of lab safety experts, and this valuable resource is intended for labs to be able to create and maintain a strong culture of safety now and for years to come.