Biosafety Levels Explained for 2020

In the U.S., the Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) specify four biosafety levels. Each level is a series of biosafety requirements for labs conducting research on biological agents. 

Laboratories classified under BSL designations must consider their level’s requirements not only during day-to-day operations, but also when selecting a biosafety laboratory space, during the design phase, and when selecting lab furniture to ensure the safe handling of infectious agents. 

What Are Biosafety Labs?

Biosafety labs are used to study infectious materials and biological agents in a safe environment. Scientists use these isolated environments to perform research on potentially hazardous materials, developing new methods of diagnostic testing, discovering potential treatment options, and improving or testing pharmaceuticals. 

The biological agents being studied in biosafety labs require a certain level of containment, ranging from mild irritants to life-threatening diseases. This will inevitably affect the type of lab benches and storage required for these facilities.

Biosafety labs come in a variety of shapes, sizes, and forms, all dependent on the individual lab’s BSL designations. All biosafety labs are designed with the intent of containing and safely researching contagious materials. 

Depending upon the nature of a particular lab’s work, precautionary measures range from handwashing upon entering and exiting to creating isolated laboratory buildings featuring complex filtered ventilation systems to prevent the spread of life-threatening airborne disease. Training for lab personnel, isolation and containment centered design, controlled airflow, specialty equipment, and intensive decontamination measures are taken to ensure safe handling of toxic or hazardous materials. 

In essence, the goal of a biosafety lab is to conduct research on biological agents like coronavirus while protecting lab personnel and the greater community from exposure. 

Biosafety Lab Requirements

Biosafety labs are all required to meet certain precautionary standards depending upon the nature of the work being done in the lab. Biosafety levels 1, 2, 3, and 4 are a series of requirements for biosafety labs. Each level identifies the level of protective measures required by a particular lab, with BSL-1 being the lowest level of biosafety and BSL-4 being the highest.

Each BSL contains specific directives for the appropriate precautionary measures at every level to avoid accidental exposure or release of pathogens into the environment. 

Biosafety Level 1

Labs designated as BSL-1 are only required to practice minimal safety precautions as their research pertains to materials that pose no or low risk to healthy adults or the community. Though often focused on infectious agents, BSL-1 labs do not handle materials that are known to consistently cause harm to human health and are therefore pose little to no risk should any find its way out of the lab. 

Educational labs like those in high school and college settings are typically BSL-1 labs. 


  • Access should be restricted to authorized and relevant persons.
  • Laboratory doors should be kept closed during working hours.
  • Laboratory doors should lock to prevent unauthorized access during off-hours.

Lab Personnel Protection

  • Lab coats, coveralls, and other protective laboratory clothing should be worn at all times.
  • Personnel must wash hands after handling infectious materials and animals. 
  • Protective eyewear should be worn when appropriate.
  • Eating, drinking, applying cosmetics, and similar activities are prohibited within the lab.
  • Lab coats, coveralls, and other protective laboratory clothing must not be worn outside of the lab environment. 
  • Street clothing and lab clothing should be kept separate.
  • Personnel must wash hands upon entering and exiting the lab. 

Key Design Features

  • Lockable door to restrict access.
  • Smooth, easy to clean floors, walls, and ceiling. 
  • Slip-resistant floors. 
  • Water, disinfectant, moderate heat, and organic solvent resistant benchtops. 
  • Handwashing basins by every exit door.
  • Adequate lighting.


  • Pipette aids (prevent using the mouth as an extra hand)
  • Biological safety cabinets
  • Disposable pipettes
  • Plastic disposable transfer loops

Agents Requiring a BSL-1 Lab Environment

  • E. coli
  • Staphylococcus
  • Bacillus subtilis

Biosafety Level 2

Labs designated as BSL-2 are required to practice all the precautions as noted in BSL-1 with a few key differences. BSL-2 labs will need biosafety cabinets class 2, and conduct research on biological agents that pose a moderate risk to healthy adults and the community. 

Toxic agents researched in BSL-2 labs are known to cause moderate disease to humans if inhaled, ingested, transmitted subdermally, or otherwise come in contact with. Often handling human blood, tissue, cells, and fluids, BSL-2 labs have more stringent regulations for personnel training, handling of contaminated objects, and the flow of personnel in and out of the work area.

Careful cleaning must be done on all laboratory workbench surfaces.


  • The international biohazard warning symbol must be displayed on the doors of rooms containing BSL-2 agents and above.
  • Access to the laboratory is limited while work is being conducted.
  • Doors should auto-close and auto-lock.

Lab Personnel Protection

  • Appropriate gloves must be worn for all procedures in which contact with blood and other fluids may occur. Hands must be washed after gloves are removed. 
  • Take extreme caution using sharps/contaminated sharps must be properly disposed of. 
  • Personnel should receive training specific to the handling of infectious pathogens. 
  • Conduct work that may result in splashes, sprays, etc. in a biological safety cabinet.
  • Daily surface decontamination. 

Key Design Features

  • Hand and eyewash stations throughout the facility. 
  • Self-closing and locking doors.
  • Autoclave, incinerator, and other waste elimination equipment. 


  • Autoclave and other means of decontamination.

Agents Requiring a BSL-2 Lab Environment

  • Hepatitis A, B, and C
  • HIV
  • Plasmodium falciparum
  • Toxoplasma gondii 

Biosafety Level 3

Labs designated as BSL-3 are required to practice all the precautions as noted in BSL-1 and BSL-2 with a few key differences. BSL-3 labs are appropriate for the handling of microbes that may cause severe or lethal disease to humans via inhalation. 

Additional measures to isolate BSL-3 labs from other areas of the building include double self-closing doors, sealed windows, filtered air systems, and stringent decontamination procedures. 

BSL-3 labs typically have specialty air systems, designed to bring clean air from non-work areas into the work area of the lab for improved air quality and filtration. Due to the highly infectious nature of agents handled in BSL-3 labs, extra precautions are taken to ensure lab personnel remain healthy, including regular medical testing and strict use of disposable laboratory clothing. 

Lab Personnel Protection

  • All members of staff are provided with medical oversight and attention to detect accidental exposure to disease.
  • Handling of all infectious material must be within a biosafety cabinet. 
  • Respiratory protective equipment should be used whenever necessary.
  • Solid or wrap front disposable protective clothing must be worn at all times. 
  • Sleeves must cover the full arm. 
  • Protective clothing must be decontaminated prior to cleaning or should be disposable. 

Key Design Features

  • BSL-3 labs should be separated from the larger facility by a hallway and two sets of self-closing, self-locking doors.
  • Sealed windows.
  • Dedicated ventilation system to direct clean air to lab workspaces and to filter laboratory air before recirculation. 
  • Seams in doors, windows, walls, etc. must be sealed to prevent the buildup of contaminants. 

Agents Requiring a BSL-3 Lab Environment

  • Mycobacterium tuberculosis 
  • SARS coronavirus
  • MERS coronavirus
  • Yellow fever virus
  • West Nile virus 
  • The COVID-19 Coronavirus is currently designated as BSL-3 however that is subject to change as research develops

Biosafety Level 4

Labs designated as BSL-4 are required to practice all the precautions as noted in BSL-1, BSL-2, and BSL-3 with a few key differences. At the highest level of biosafety, BSL-4 labs research highly-infectious agents that pose serious and life-threatening risks to human health. 

Agents studied in BSL-4 labs are often newly discovered diseases of indeterminate risk and without known causes, cures, or treatments. Because of the risk associated with the work done in BSL-4 labs, extreme caution is required in the design and operation of these facilities. 

To prevent the spread of potentially incurable disease, BSL-4 labs have restricted access, should be isolated or stand-alone buildings, and implement stringent decontamination practices. 


  • BSL-4 labs should not be accessible by anyone but authorized personnel. Ideally, BSL-4 labs will be entirely separate from other buildings or unrestricted traffic areas. 
  • All individuals entering or exiting the facility must be recorded.

Lab Personnel Protection

  • All personnel must change into appropriate clothing upon arrival. 
  • All personnel must shower before changing into street clothes upon their exit.
  • Personnel must conduct all work in Class II or III biosafety cabinets while wearing positive-pressure suits.
  • Materials leaving biosafety cabinets must pass through a decontamination phase.

Key Design Features

  • A separate building or clearly delineated zone is required when choosing a BSL-4 location. 
  • Tightly controlled airflow to prevent contaminated air from entering the surrounding environment. 
  • Complex filtering systems to remove contagions and airborne illnesses from ventilated air.

Agents Requiring a BSL-4 Lab Environment

  • Smallpox
  • Ebola virus
  • Marburg virus
  • Hendra virus

Need Help Planning a Biosafety Lab?

OnePointe Solutions manufacturers, designs, supplies, and install biosafety cabinets for all levels. Our lab designers work with you to design your ideal lab space that is fully compliant with CDC and WHO biosafety standard. We provide 100% design and consultation services and offer a full line of scientific and technical furniture and installation.

Contact us by calling (866) 612-7312 or fill out an online contact form. One of our sales reps will be touch to discuss your project.

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