A Biosafety Level (BSL) is a set of biocontainment precautions required to isolate
dangerous biological agents in an enclosed laboratory facility.
A Biosafety Level (BSL) is a set of biocontainment precautions (i.e. PPE, procedures,
equipment, etc.) required to isolate dangerous biological agents in an enclosed laboratory
facility. In the United States, the Centers for Disease Control and Prevention (CDC)
have specified these levels. The levels (BSL-1,2,3 and 4) are designated in ascending
order, by degree of protection provided to personnel, the environment, and the community.
Standard microbiological practices are common to all laboratories. Each BSL builds
on and includes the biocontainment procedures and precautions employed at lower levels
of containment. Selection of the appropriate BSL is based on a thorough biosafety
risk assessment of the biological agents and laboratory procedural hazards that will
be used in the laboratory. In addition, there are also designated biocontainment levels
for laboratory work involving animals. The levels (ABSL-1,2,3, and 4) are designated
in ascending order.
BSL 1 - is suitable for work involving well-characterized agents not known to consistently
cause disease in immunocompetent adult humans and present minimal potential hazard
to laboratory personnel and the environment. Work is typically conducted on open bench
tops using standard microbiological practices. Special containment or facility design
is not required but may be used as determined by appropriate risk assessment. Laboratory
personnel receive specific training in the procedures conducted in the laboratory
and are supervised by a scientist with training in microbiology or a related science.
BSL 2 - is suitable for work with agents associated with human disease and pose moderate
potential hazards to personnel and the environment. BSL-2 differs from BSL-1 primarily
because:
Laboratory personnel receive specific training in handling pathogenic agents and are
supervised by scientists competent in handling infectious agents and associated procedures.
Access to the laboratory is restricted when work is being conducted.
All procedures in which infectious aerosols or splashes may be created are conducted
in BSCs or other physical containment.
BSL 3 - is suitable for work involving indigenous or exotic agents which may cause serious
or potentially lethal disease as a result of exposure by inhalation. Laboratory personnel
receive specific training in handling pathogenic and potentially lethal agents and
must be supervised by scientists competent in handling infectious agents and associated
procedures. All procedures involving the manipulation of infectious materials must
be conducted within BSCs or other physical containment devices. A BSL-3 laboratory
has special engineering and design features.
BSL 4 - is required for work with dangerous and exotic agents that pose a high risk of
aerosol-transmitted laboratory infections and life-threatening disease. BSL-4 laboratories
are not allowed at Stony Brook University.
ABSL 1 - is suitable for animal work involving well-characterized agents not known to consistently
cause disease in immunocompetent adult humans and present minimal potential hazard
to laboratory personnel and the environment. Work is typically conducted on open bench
tops using standard microbiological practices. Special containment or facility design
is not required but may be used as determined by appropriate risk assessment. Laboratory
personnel receive specific training in the procedures conducted in the laboratory
and are supervised by a scientist with training in microbiology or a related science.
ABSL-2 - builds upon the practices, procedures, containment equipment, and facility requirements
of ABSL-1. ABSL-2 is suitable for work involving laboratory animals infected with
agents associated with human disease and poses moderate potential hazards to personnel
and the environment. It also addresses hazards from ingestion and from percutaneous
and mucus membrane exposure. ABSL-2 requires that, in addition to the requirements
for ABSL-1, a BSC or other physical containment equipment is used when procedures
involve the manipulation of infectious materials or where aerosols or splashes may
be created. Appropriate PPE is worn to reduce exposure to infectious agents, animals,
and contaminated equipment. An appropriate occupational health program is in place,
as determined by risk assessment.
ABSL-3 - involves practices suitable for work with laboratory animals infected with indigenous
or exotic agents which may cause serious or potentially lethal disease as a result
of exposure by inhalation. ABSL-3 builds upon the standard practices, procedures,
containment equipment, and facility requirements of ABSL-2. The ABSL-3 facility has
special engineering and design features. ABSL-3 requires that in addition to the requirements
for ABSL-2, all procedures are conducted in BSCs or by use of other physical containment
equipment. Inward airflow at the containment boundary is maintained. Handwashing
sinks are capable of hands-free operation. Appropriate PPE is worn to reduce exposure
to infectious agents, animals, and contaminated equipment.
ABSL-4 - is required for work with animals infected with dangerous and exotic agents that
pose a high individual risk of aerosol-transmitted laboratory infections and life-threatening
diseases that are frequently fatal agents for which there are no vaccines or treatments.
ABSL-4 laboratories are not allowed at Stony Brook University.
