Animal Biosafety Level 2 (ABSL2)
Animal Biosafety Level 2 involves practices for work with those agents
associated with human disease. It addresses hazards from ingestion as
well as from percutaneous and mucous membrane exposure. ABSL-2 builds
upon the practices, procedures, containment equipment, and facility
requirements of ABSL-1.
A. Standard Practices
B. Special Practices
- Aside from the standard policies, procedures,
and protocols for emergency situations established by the facility
director, appropriate special policies and procedures should be
developed as needed and approved by the Institutional Animal Care and Use Committee (IACUC)
and the Institutional Biosafety Committee (IBC).
- Access to the animal room is limited to the
fewest number of individuals possible. Personnel who must enter the
room for program or service purposes when work is in progress are
advised of the potential hazard.
- An appropriate medical surveillance program is
in place. All personnel receive appropriate immunizations or
tests for the agents handled or potentially present (e.g., hepatitis B
vaccine, TB skin testing). When appropriate, a serum surveillance
system should be implemented.
- A biosafety manual is prepared or adopted.
Personnel are advised of special hazards, and are required to
read and follow instructions on practices and procedures.
- Eating, drinking, smoking, handling contact
lenses, applying cosmetics, and storing food for human use should only
be done in designated areas and are not permitted in animal or
- All procedures are carefully performed to
minimize the creation of aerosols or splatters.
- Equipment and work surfaces in the room are
routinely decontaminated with an effective disinfectant after work with
the infectious agent, and especially after overt spills, splashes, or
other contamination by infectious materials.
- All infectious samples are collected, labeled,
transported, and processed in a manner that contains and prevents
transmission of the agent(s). All wastes from the animal room
(including animal tissues, carcasses, contaminated bedding, unused
feed, sharps, and other refuse) are transported from the animal room in
leak-proof, covered containers for appropriate disposal in compliance
with applicable institutional or local requirements. The outer
surface of the containers is disinfected prior to moving the material.
Autoclaving of the contents prior to incineration is recommended.
- Policies for the safe handling of sharps are
- Needles and syringes or other sharp
instruments are restricted for use in the animal facility only when
there is no alternative, such as for parenteral injection, blood
collection, or aspiration of fluids from laboratory animals and
- Syringes that re-sheathe the needle,
needle-less systems, and other safe devices should be used when
- Plastic ware should be substituted for
glassware whenever possible.
- Personnel wash their hands after handling
cultures and animals, after removing gloves, and before leaving the
- A biohazard sign must be posted on the entrance
to the animal room whenever infectious agents are present. The hazard
warning sign identifies the infectious agent(s) in use, lists the name
and telephone number of the responsible person(s), and indicates the
special requirements (e.g., the need for immunizations and respirators)
for entering the animal room.
- An insect and rodent control program is in
effect (see BMBL 4th Edition: Appendix G).
C. Safety Equipment (Primary
- Animal care laboratory and
support personnel receive appropriate training on the potential hazards
associated with the work involved, the necessary precautions to prevent
exposures, and the exposure evaluation procedures. Personnel
receive annual updates, or additional training as necessary for
procedural or policy changes. Records of all training provided
are maintained. In general, persons who may be at increased risk
of acquiring infection, or for whom infection might be unusually
hazardous, are not allowed in the animal facility unless special
procedures can eliminate the extra risk.
- Only animals used for the
experiment(s) are allowed in the room.
- All equipment must be
appropriately decontaminated prior to removal from the room.
- Spills and accidents which
result in overt exposures to infectious materials must be immediately
reported to the facility director. Medical evaluation,
surveillance, and treatment are provided as appropriate and written
records are maintained.
D. Facilities (Secondary
- Gowns, uniforms, or laboratory
coats are worn while in the animal room. The laboratory coat is removed
and left in the animal room. Gowns, uniforms, and laboratory
coats are removed before leaving the animal facility. Gloves are
worn when handling infected animals and when skin contact with
infectious materials is unavoidable.
- Personal protective equipment is
used based on risk assessment determinations. Appropriate
face/eye and respiratory protection is worn by all personnel entering
animal rooms that house nonhuman primates.
- Biological safety cabinets,
other physical containment devices, and/or personal protective
equipment (e.g., respirators, face shields) are used whenever
conducting procedures with a high potential for creating aerosols.
These include necropsy of infected animals, harvesting of tissues
or fluids from infected animals or eggs, or intranasal inoculation of
- When needed, animals are housed
in primary biosafety containment equipment appropriate for the animal
species. Filter top cages are always handled in properly designed
and operating animal biocontainment cabinets recommended for rodents.
- The animal facility is separated
from areas that are open to unrestricted personnel traffic within the
- Access to the facility is
limited by secure locked doors. External doors are self-closing
and self-locking. Doors to animal rooms open inward, are
self-closing, and are kept closed when experimental animals are
present. Cubicle room inner doors may open outward or be
horizontal or vertical sliding.
- The animal facility is designed,
constructed, and maintained to facilitate cleaning and housekeeping.
The interior surfaces (walls, floors, and ceilings) are water
- Internal facility appurtenances,
such as light fixtures, air ducts, and utility pipes, are arranged to
minimize horizontal surface areas.
- Windows are not recommended. Any
windows must be resistant to breakage and should be sealed.
- If floor drains are provided,
the traps are always filled with an appropriate disinfectant.
- Exhaust air is discharged to the
outside without being recirculated to other rooms. Ventilation
should be provided in accordance with criteria from Guide for Care and
Use of Laboratory Animals, latest edition. The direction of
airflow in the animal facility is inward; animal rooms should maintain
negative pressure compared to adjoining hallways.
- Cages are washed manually or in
an appropriate cage washer. The mechanical cage washer should
have a final rinse temperature of at least 180F.
- An autoclave is available in the
animal facility to decontaminate infectious waste.
- A hand washing sink is in the
animal room where infected animals are housed, as well as elsewhere in
- Illumination is adequate for all
activities, avoiding reflections and glare that could impede vision.
Reproduced from "Biosafety in Microbiological and Biomedical
Laboratories, BMBL 4th Edition" with permission from the Center for
Disease Control (CDC).