CDC Biosafety Levels: BSL-1, BSL-2, BSL-3, BSL-4

CDC Biosafety Levels are prevention mechanisms aimed at reducing the risk of exposure to potentially harmful microbes as well as reducing contamination of the surrounding environment. The US Center for Disease Control has set the CDC biosafety levels to contain...

by | Jan 31, 2023

CDC Biosafety Levels are prevention mechanisms aimed at reducing the risk of exposure to potentially harmful microbes as well as reducing contamination of the surrounding environment. The US Center for Disease Control has set the CDC biosafety levels to contain microbes and other disease-causing agents.

US Center for Disease Control CDC Biosafety Levels, BSL-1, BSL-2, BSL-3, BSL-4

US Center for Disease Control CDC Biosafety Levels

There are four CDC biosafety levels, or BSLs, aimed at safeguarding laboratory workers, the surrounding environment, and even the community. Each biosafety level has a specific set of protocols for containing all microbes, chemicals, or other agents. The levels are ranked based on the agents worked with, with 1 being the lowest risk microbes, and 4 being the highest. Biosafety levels are determined by the risks the microbe poses, the severity of infection, transmissibility, the nature of the work being conducted, the origin of the microbe, the agent in question, and the route of exposure.


The lowest of the four biosafety levels, level 1 applies to biosafety laboratory settings in which the microbes being studied are of minimal risk and pose little threat as they are not known to be disease-causing to healthy individuals. In a level 1 laboratory, work can be performed on an open bench or table.


A biosafety BSL-2 laboratory is more restrictive than a biosafety BSL-1 laboratory, meaning any outside personnel or anyone with an increased risk is restricted from entering while work is in progress. BSL-2 laboratories follow the same standards as biosafety BSL-1 plus more, as these biosafety laboratories deal with indigenous microbes, those that cause diseases, so they pose a greater threat to personnel and the environment.


Biosafety laboratories

Biosafety laboratories

In a BSL-3 laboratory, access to who can enter and exit is continuously monitored and personnel must pass through two sets of self-closing and locking doors. The work performed in this level of laboratory is generally with indigenous or even exotic microbes that can cause serious or even lethal diseases through inhalation. The work here is often even registered with the government and the personnel in these biosafety laboratories are under surveillance by medical professionals.


BSL-4 laboratories are the highest level of biosafety and are somewhat rare as the work done is with dangerous and exotic microbes. Generally, the microbes studied in a BSL-4 laboratory are fatal and have no treatment or vaccine. These biosafety laboratories are isolated, usually located in separate buildings, and have their own supply and exhaust of air and decontamination systems. Laboratory personnel are required to change their clothing upon entering and exiting the lab and are also required to shower upon departure. Workers also generally wear air-supplied bodysuits while working with the microbes. assists companies and governments with their research and development studies that need to be conducted in CDC Biosafety Level Laboratories. Below are some examples of projects that we have facilitated:

  •  Pharmaceutical contract research organization CRO needed to perform virus neutralization assays in vitro (BSL3 required!).
  • BSL-3, FDA GLP Europe and Eastern Europe preclinical contract research organization needed for GLP Hepatitis C vaccine candidate
  • Molecular Diagnostic Company seeks BSL4 Laboratory services to develop BSL4 Ebola infectivity assays.
  • University Researchers need a BSL-2 Contract Research Organization CRO for BSL2 studies in non-traditional models; for example,
  • Medical Instrument Company needs India FDA GMP and UKAS Biosafety Level 3 (BS-3) BSL-3 Laboratory for BSL-3 Testing
  • Preclinical Laboratory, Contract Research Organization CRO needed for Influenza vaccine proof-of-concept studies. Peptide
  • GLP Southeast USA microbiology laboratory is needed for GLP microbiology testing. Measure the antimicrobial efficacy
  • USA GMP / GLP bioanalytical laboratory needed for GMP HPLC testing of Geneticin in virus samples (requires BSL2 lab)
  • Eastern USA ABSL2, BSL2 Preclinical Contract Research Organization needed to perform an I.V. challenge of mice with MRSA. We
  • US BSL-3, Non-GLP Preclinical Contract Research Organization needed for Preclinical Drug Development, efficacy testing
  • Preclinical Contract Research Organization CRO is needed for preclinical Immunization of (1)cattle, (2)cats, and (3) dogs.
  • USA GMP, GLP, FDA Microbiology Laboratory required for automated BSL 3 cell viability testing on mycobacteria
  • USA West Coast GMP Bioanalytical Laboratory needed for gelatin detection and identification in a BSL-2 biotech product
  • European lab with BSL2 certification needed to test for * isolation of a bacterial clone * selection interaction process using clients
  • GLP/GMP BSL III microbiology laboratory is needed for sterility testing and Mycoplasma testing on Flu samples.
  • BSL3 microbiology laboratory needed for ATTC microbiology diagnostics validation by growing ATTC Rickettsial strains, extracting
  • GMP-compliant BSL2 virology laboratory for vaccines electron microscopy.
  • GLP BSL virology laboratory is needed for viral suspension testing of the HPAI-H5N1 pathogenic virus with the product, followed by testing for the virus
  • BSL-3 microbiology and molecular biology laboratory needed for exposure of blood mononuclear cells to organisms
  • Virology and immunology laboratory needed for Viral re-activation in mice. Infect mice with polyomavirus. Allow virus infection

And many more which can be seen at CDC Biosafety Level Research and Development Projects.


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