BIOLOGICAL SAFETY CABINET PROGRAM
TABLE OF CONTENTS:
1.
INTRODUCTION
2.
PURPOSE AND SCOPE
3.
SELECTION AND INSTALLATION
4.
USE OF BIOLOGICAL SAFETY CABINETS
5.
CERTIFICATION OF BIOLOGICAL SAFETY CABINETS
6.
PROGRAM ADMINISTRATION
7.
RESPONSIBILITIES
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EHS-M-30
Issue Date: 11/05/07
Reviewed: MAR
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USC BIOLOGICAL SAFETY CABINET PROGRAM
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1. INTRODUCTION
The biological safety cabinets (BSC) are used at the University of South Carolina as a primary
means of containment for working safely with infectious microorganisms. They act as primary
barriers to prevent the escape of biological aerosols into the laboratory environment. This is
an important function, because most laboratory techniques (e.g. pipetting, vortexing,
sonicating) are known to produce inadvertent aerosols that can be readily inhaled by the
laboratory worker. BSCs are only one part of an overall biosafety program which requires
consistent use of good microbiological practices, use of a primary containment equipment
and proper containment facility design.
BSCs are designed, in varying combinations, for:
Personnel Protection: Protects personnel from harmful agents inside the BSC.
Product Protection: Protects the work, product, experiment or procedure performed in
the BSC from contaminants in the laboratory environment or from cross contamination
inside the cabinet.
Environmental Protection: Protects the environment from contaminants contained in the
BSC.
There are three broad types of BSCs, each with varying degrees of protection:
Class I BSCs provide personnel and environmental protection, but not product
protection. It is similar in air movement to a chemical fume hood, but has a HEPA filter in
the exhaust system to protect the environment.
Class II BSCs provide personnel, environmental and product protection. Airflow is drawn
into the front grille of the cabinet, providing personnel protection. In addition, the
downward laminar flow of HEPA-filtered air provides product protection by minimizing
the chance of cross-contamination across the work surface of the cabinet. Class II BSCs
are appropriate for work with agents assigned to biosafety levels 1-3. This is the most
common type of BSC used at USC.
Class III BSCs are designed for work with highly infectious microbiological agents and
provides maximum protection for the environment and the worker. Both supply and
exhaust air are HEPA filtered. Class III BSCs are required for Biosafety Level (BSL) IV work.
Currently, there is no BSL IV work in progress at USC, and there are no Class III BSCs
installed.
Laminar Flow Benches are designed for project protection only, and are never to be
used when working with cell cultures or infectious materials. Annual certification of
laminar flow benches is not required.
2. PURPOSE AND SCOPE
The purpose of the BSC Program is to establish University policy for the selection, use,
maintenance and certification of biological safety cabinets.
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EHS-M-30
Issue Date: 11/05/07
Reviewed: MAR
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3. SELECTION AND INSTALLATION
The Class II, Type A2 BSC is the most commonly used cabinet in the USC research labs. This type
of BSC provides personnel, product and environmental protection from hazardous particulates
such as biological agents that require containment at Biosafety Level 1, 2 or 3. HEPA filtered
exhaust air from a Class II, Type A2 BSC can be safely re-circulated back into the laboratory
environment if the cabinet is tested and certified at least annually and operated according to
manufacturer’s recommendations.
BSCs can also be connected to the laboratory exhaust system by either a thimble (canopy)
connection or a direct (hard) connection. This would allow for 100% of the filtered exhaust air to
be discharged out of the laboratory. Since none of the air is re-circulated, these cabinets may
be used for work with biological agents treated with volatile toxic chemicals. Provisions to assure
proper safety cabinet performance and air system operation must be verified. The expense for
installation and maintenance of a total-exhaust BSC is much higher, and therefore should only
be selected and installed when justified based on the specific type of research being
conducted in the lab. Any lab planning to purchase and install a total-exhaust cabinet (i.e.
Class II, Type B2) should notify Environmental Health and Safety prior to ordering the cabinet.
BSCs should be located away from doors, windows that can be opened, and heavily traveled
laboratory areas. This will help to minimize air pattern disruption in the cabinet. Air supply diffusers
or exhaust vents should not be placed directly over or in front of BSCs where the movement of
air can affect the airflow of the cabinet. A 12 inch clearance should be provided behind and on
each side of a BSC to allow easy access for maintenance, and to ensure that the air return to
the laboratory is not hindered. Open flames, such as gas burners, should not be used in a BSC.
The proper selection and installation of BSCs must be made in accordance with the most recent
edition of Primary Containment of Biohazards: Selection, Installation and Use of Biological Safety
Cabinets. This document is available online and is published jointly by the U.S. Department of
Health and Human Services, Centers for Disease Control and Prevention, and National Institutes
of Health.
4. USE OF BIOLOGICAL SAFETY CABINETS
A properly certified and operational BSC is an effective engineering control which must be
used in concert with appropriate work practices, procedures and other administrative
controls to reduce the risk of exposure to infectious microorganisms. The following work
practices and procedures should be in place when working in a BSC.
(1) Planning
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Thoroughly understand procedures and equipment required before beginning work.
Arrange for minimal disruptions, such as room traffic or entry into the room, while the
cabinet is in use.
(2) Start-Up
•
Turn off UV light if in use. Ensure that the sash is set in the correct operating position.
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EHS-M-30
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Reviewed: MAR
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Turn on fluorescent light and cabinet blower.
Check the return air grilles for obstructions, and note the pressure gauge reading.
Allow the cabinet to operate unobstructed for at least fifteen minutes.
Wash hands and arms thoroughly with soap.
Wear a long sleeved lab coat with knit cuffs and over-the-cuff gloves.
Make sure that all waste containers are located inside the BSC before starting work.
(3) Surface Decontamination (before work)
•
Wipe down the interior surfaces of the cabinet with 10% bleach, followed in 5 to 10
minutes with 70% ethanol to prevent pitting of the stainless steel, and allow to dry.
(4) Loading Materials and Equipment
•
•
•
Only load the materials required for the procedure. Do not overload the cabinet.
Do not obstruct the front, side, or rear return air grilles.
Large objects should not be placed close together. After loading the cabinet, wait
two to three minutes to purge airborne contaminants from the work area.
(5) Work Techniques
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Keep all materials at least four inches inside the sash, and perform all contaminated
operations as far to the rear of the work area as possible.
Segregate all clean and contaminated materials in the work area and arrange
materials to minimize the movement of contaminated materials into clean areas.
Keep all discarded, contaminated material to the rear of the cabinet.
Avoid moving materials or excessive motion of the operator’s hands and arms
through the front access opening during use.
Open flames SHOULD NOT be used.
Use proper aseptic technique.
Avoid using techniques or procedures that disrupt the air flow pattern of the cabinet.
If there is a spill or splatter during use, all objects in the cabinet should be surface
decontaminated before removal. Thoroughly disinfect the working area of the
cabinet WHILE IT IS STILL IN OPERATION. This will prevent the release of contaminants
from the cabinet.
(6) Final Purging
•
Upon completion of work, the cabinet should be allowed to operate for three to five
minutes undisturbed, to purge airborne contaminants from the work area.
(7) Unloading Materials and Equipment
•
•
•
Disposable contaminated objects, including gloves, should be placed in disposal
pans or autoclave bags inside the BSC after use.
Reusable objects in contact with contaminated material should be surface
decontaminated before removal from the cabinet.
All open trays or containers should be covered before being removed from the
cabinet.
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EHS-M-30
Issue Date: 11/05/07
Reviewed: MAR
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(8) Surface Decontamination – after work
•
Wipe down the interior surfaces of the cabinet with 10% bleach, followed in 5 to 10
minutes with 70% ethanol to prevent pitting of the stainless steel.
5. CERTIFICATION OF BIOLOGICAL SAFETY CABINETS
(1) General Certification Requirements:
(a) All Class II BSCs must be tested and certified at least annually to ensure continued
proper operation.
(b) All Class II BSCs will be tested and certified in accordance with specifications in
NSF Standard 49 Annex “F” and the manufacturer’s specifications.
(c) The operational integrity must be validated by certification before a newly
installed BSC is used and after a BSC has been repaired or relocated.
(d) After a BSC has been certified, a label will be prominently affixed to the front of
the BSC, displaying the date of certification and name of the certifier.
(e) One copy of the certification report will be provided to the laboratory staff.
(f) Only NSF accredited field certifiers will be used to test and certify BSCs.
(2) Certification Requirements for Class II BSCs. All Class II BSCs will be tested and
certified as per NSF/ANSI 49 – 2004 specifications, including:
(a) Downflow Velocity and Volume Test
(b) Inflow Velocity Test
(c) Airflow Smoke Patterns Test
(d) HEPA Filter Leak Test
(e) Cabinet Leak Test
(f) Electrical Leakage and Ground Circuit Resistance and Polarity Tests
(g) Lighting Intensity Test
(h) Vibration Test
(i) Noise Level Test
(j) UV Lamp Test
_____________________________________________________________________________________________________________________________________
EHS-M-30
Issue Date: 11/05/07
Reviewed: MAR
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(3) Gas Decontamination
(a) BSCs that have been used for work involving infectious materials must be
decontaminated before HEPA filters are changed or internal repair work is done.
(b) Before a BSC is relocated, a risk assessment which considers the agents
manipulated within the BSC must be done to determine the need for
decontamination.
(c) The most common decontamination method uses formaldehyde gas, although
more recently hydrogen peroxide vapor has been used successfully.
(d) Lab personnel should contact Environmental Health and Safety for guidance
when determining the need for gas decontamination.
6. PROGRAM ADMINISTRATION
(1) Coordination of certification. Primary responsibility for the coordination of annual
BSC certifications is held by the following:
(a) USC-Columbia – USC Environmental Health and Safety
(b) USC School of Medicine, including Medical Park buildings – USC School of
Medicine Safety Office
(2) Funding:
(a) USC Environmental Health and Safety provides funding for annual certification of
BSCs in laboratories at the USC-Columbia campus.
(b) The School of Medicine Health and Safety Office provides funding for annual
certification of BSCs at the USC School of Medicine and Medical Park buildings.
(3) BSC Inventory:
(a) USC Environmental Health and Safety maintains a database inventory of BSCs for
USC-Columbia and the School of Medicine. Individual hoods are identified by a
unique tracking number. Each hoods class and type, certification date and
location are included in the database. Certification dates are reported to EHS so
the database can be updated.
(b) All new BSC installations will be reported to EHS for addition to the database.
(c) EHS will share this database with the designated certification vendor to ensure all
BSCs are certified annually and certification records are accurately maintained.
_____________________________________________________________________________________________________________________________________
EHS-M-30
Issue Date: 11/05/07
Reviewed: MAR
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7. RESPONSIBILITIES
1) Facility Services Maintenance – Research Group
School of Medicine Safety Office
a) Coordinates annual certification for BSCs at the USC School of Medicine and
Medical Park buildings.
b) Reports to EHS any BSC maintenance/repairs, post-repair certifications, and BSC
relocations or new installations.
2) Environmental Health and Safety
a) Maintains an updated database of all BSCs in laboratories at each USC campus.
b) Coordinates with the designated certification vendor to ensure all BSCs in the
database are certified annually.
3) Principal Investigators/BSC Users
a) Ensure the implementation of appropriate work practices when using a BSC,
consistent with this program and biological safety training.
b) Promptly report any problems with BSCs to the appropriate maintenance
personnel so that necessary maintenance or repairs can be performed.
c) Report the relocation or new installation of BSCs to Environmental Health and
Safety so that each cabinet can be certified prior to use. This will also ensure the
BSC certification database accurately reflects the location of each cabinet
requiring annual certification.
_____________________________________________________________________________________________________________________________________
EHS-M-30
Issue Date: 11/05/07
Reviewed: MAR
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