BSL3

Biosafety Level 3 (BSL-3)

Biosafety Level 3 (BSL-3) is a set of biocontainment precautions required to isolate dangerous biological agents in an enclosed laboratory facility. It is one of the four levels of biosafety, with BSL-1 being the lowest and BSL-4 being the highest. BSL-3 is applicable to clinical, diagnostic, teaching, research, or production facilities where work is performed with indigenous or exotic agents that may cause serious or potentially lethal disease through inhalation exposure.

Overview

BSL-3 laboratories are designed to be easily decontaminated and are equipped with specialized ventilation systems to prevent the release of infectious agents. The laboratory is maintained at negative air pressure to ensure that air flows into the laboratory from adjacent areas, preventing the escape of pathogens.

Design and Construction

BSL-3 laboratories must be constructed with specific features to ensure containment and safety:

• Access Control: Entry to the laboratory is restricted to authorized personnel only. Access is controlled by a series of self-closing doors.
• Ventilation: The laboratory must have a ventilation system that provides directional airflow from clean to potentially contaminated areas. Air from the laboratory is not recirculated and is filtered through high-efficiency particulate air (HEPA) filters before being exhausted.
• Surfaces: All surfaces in the laboratory, including floors, walls, and ceilings, must be smooth, impervious to liquids, and resistant to chemicals and disinfectants to facilitate cleaning and decontamination.
• Decontamination: Facilities for decontaminating waste and equipment, such as autoclaves, must be available within the laboratory.

Safety Practices

Personnel working in BSL-3 laboratories must adhere to strict safety practices to prevent exposure to infectious agents:

• Personal Protective Equipment (PPE): Laboratory personnel must wear appropriate PPE, including lab coats, gloves, and respiratory protection, as necessary.
• Training: All personnel must receive specialized training in handling pathogenic and potentially lethal agents and must be supervised by scientists competent in handling infectious agents and associated procedures.
• Procedures: All procedures involving the manipulation of infectious materials must be conducted within a biological safety cabinet (BSC) or other physical containment devices.

Examples of BSL-3 Pathogens

BSL-3 laboratories are used to study a variety of pathogens that pose a risk to human health. Examples include:

• Mycobacterium tuberculosis, the bacterium that causes tuberculosis.
• SARS-CoV-2, the virus responsible for COVID-19.
• Bacillus anthracis, the bacterium that causes anthrax.

Also see

• Biosafety Level 1
• Biosafety Level 2
• Biosafety Level 4
• Biological safety cabinet
• Pathogen