Laboratory Biosafety Levels
- There are four levels of biosafety used to designate and regulate lab work with microorganisms.
- Each level is designed to prevent lab-acquired infections and to protect the environment from potentially hazardous agents.
- The higher the level of the biosafety lab, the more stringent the level of protection required to work in these areas.
BSL-1: Microorganisms not known to cause disease in healthy adult human beings.
- Potential hazards to laboratory personnel and the environment are minimal.
- Work is conducted on open bench tops using standard microbiological practices (lab coats, safety glasses and gloves).
- Lab personnel have specific training in the procedures conducted in the lab and are supervised by a scientist with general training in microbiology or a related science.
- BSL-1 labs are located in high school and college-level biology and chemistry classrooms and research institutions.
BSL-2: Microorganisms of moderate potential hazard to personnel and the environment.
- Lab personnel have specific training in handling pathogenic agents and are supervised by scientists competent in handling infectious agents and associated procedures.
- Access to the lab is limited when work is being conducted.
- All procedures in which infectious aerosols or splashes may be created are conducted in biological safety cabinets or other physical containment equipment.
- BSL-2 labs are located in research institutions, essentially all hospitals, and medical and veterinary schools.
- An example of a microorganism that would be studied in a NBAF BSL-2 lab is the inactivated virus that causes foot and mouth disease.
BSL-3: Microorganisms present in the United States, and foreign and emerging agents that may cause serious consequences in livestock but are not harmful to human beings because of available protective measures.
- Lab personnel have specific training in handling pathogenic microbes potentially lethal to animals and are supervised by trained scientists who are experienced in working with these agents and associated procedures.
- Access to the lab is controlled (i.e., card reader for entry; self-sealing, double door access, etc.)
- All procedures involving the manipulation of infectious materials are conducted within biological safety cabinets or other physical containment devices, or by personnel wearing appropriate personal protective clothing and equipment.
- BSL-3 labs have special engineering and design features to enhance safety.
- BSL-3 labs are located in research institutions, hospitals, and medical and veterinary schools.
- An example of a microorganism that would be studied in a NBAF BSL-3 lab is the live virus that causes foot and mouth disease in cloven-hoofed animals.
BSL-4: Microorganisms that pose a high risk of life-threatening disease and for which there is no known vaccine or therapy.
- Lab personnel have specific and thorough training in handling extremely hazardous infectious agents and fully understand all containment functions, practices, equipment and lab design characteristics.
- Lab personnel are supervised by trained scientists who are experienced in working with the microorganisms and with associated procedures.
- Access to the lab is strictly controlled. The facility is in a controlled area within a building, which is completely isolated from all other areas.
- Currently, there are four BSL-4 facilities operating in the Following United States populated urban areas: Atlanta, Georgia; Fort Detrick, Maryland; Galveston, Texas; and San Antonio, Texas. There has never been a public exposure at a BSL-4 lab in the United States.
- Examples of microorganisms that could possibly be studied in a NBAF BSL-4 lab include Nipah and Hendra viruses, both of which are emerging zoonotic diseases that can spread from their natural reservoir to human beings, and are often fatal.
Glossary of Technical Terms
Biological Safety Cabinets (BSCs): The most effective and the most commonly used primary containment devices in laboratories working with infectious agents. There are three general types available (Class I, II, III). Properly maintained Class I and II BSCs, when used in conjunction with good microbiological techniques, provide an effective containment system for safe manipulation of moderate and high-risk microorganisms(biosafety level 2 and 3 microorganisms). Class II BSCs also protect the research material itself through high-efficiency particulate air filtration (HEPA filtration) of the air flow down across the work surface. Class III cabinets offer the maximum protection to laboratory personnel because all hazardous materials are contained in a totally enclosed cabinet.
Biosafety Levels (BSLs): There are four levels of biosafety used to designate and regulate lab work with microorganisms. The range is BSL-1 in which the microorganisms are not known to cause disease in healthy adult human beings to BSL-4 in which the microorganisms pose a risk of life-threatening disease and for which there is no known vaccine or therapy. BSL-3Ag refers to research involving large agricultural animals. There are guidelines in place to ensure safe work sites through a combination of engineering controls, management policies, work practices, and procedures. Increasing levels of personnel and environmental protection are provided for by the different biosafety levels used in microbiological/biomedical laboratories. The higher the level of the biosafety lab, the more stringent the level of protection.
Countermeasures: A collective term used in biocontainment laboratories to include vaccines, biotherapeutics, diagnostic assays, therapies, and vector control.
Diagnostic Assay: A test to determine presence or absence of infectious agents or antibodies to determine if an animal has or has been exposed to an agent.
Environmental Impact Statement: A document required of federal agencies by the National Environmental Policy Act for major federal actions that may significantly affect the quality of the environment. A tool for decisionmaking, it describes, analyzes, and compares the potential environmental impacts of the alternatives to accomplish the purpose and need to which the agency is responding.
Glovebox: A sealed container designed to allow a trained scientist to manipulate microorganisms while being in a different containment level than that of the agent they are manipulating. Built into the sides of the glovebox are two glove ports arranged in such a way that one can place their hands into the ports, into gloves and perform tasks inside the box without breaking the seal. There are three general types available (Class I, II, III) based on the material the box and gloves are made of.
High-Consequence Foreign Animal Diseases (FADs): Diseases not present in the United States that are capable of rapidly spreading and causing high numbers of deaths and/or devastating economic consequences (e.g., foot and mouth disease).
Homeland Security Presidential Directives 9 and 10: These directives established a national goal to protect agricultural infrastructure to ensure our livestock and food safety and security.
Host: In biology, a host is an organism that harbors a virus or parasite, typically providing nourishment and shelter.
National Bio and Agro-Defense Facility (NBAF): Proposed facility that would address both current and future requirements in research, diagnostics, and training for combating high-consequence agricultural threats. Research would focus on early development and discovery of vaccines and diagnostic tests for these important agricultural diseases.
National Environmental Policy Act (NEPA): Requires the preparation of an environmental impact statement (EIS) for major federal actions that may significantly affect the quality of the environment. In NEPA, the term “environment” encompasses the natural and physical environment (i.e., air, water, geography, and geology), as well as the relationship of people with that environment (i.e., health and safety, socioeconomic conditions, cultural resources, noise, and aesthetics).
Natural Reservoir: Refers to the long-term host of the pathogen of an infectious disease. It is often the case that hosts do not get severely ill.
Pathogen or Infectious Agent: A biological agent that causes disease or illness to its host. The term is most often used for agents that disrupt the normal physiology of an animal or person.
Plum Island Animal Disease Center (PIADC): U.S. laboratory for the diagnosis, research, and training for foreign animal diseases. The U.S. Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) Foreign Animal Disease Diagnostic Laboratory is located at PIADC. This laboratory has the capability of diagnosing over 30 foreign animal diseases and is responsible for educating veterinarians in the recognition and diagnosis of these diseases. The USDA Agricultural Research Service (ARS) operates a program focused on basic discovery and research of foreign animal diseases. The DHS scientific program focuses primarily on the advanced development of vaccines and other countermeasures.
Wildlife Reservoir: Wildlife are normally defined as wild, free-roaming animals (e.g., mammals, birds, fish, reptiles, and amphibians); therefore, this refers to a wild animal as long-term host of the pathogen of an infectious disease. It is often the case that hosts do not get the disease carried by the pathogen or it does not show symptoms of the disease and is non-lethal.
Zoonotic: A term for diseases transmitted by animals to humans.