Department of Physiology
Procedure No:
PHY/SOP/EQ03
Revision No:
001
Title:
Effective Date :
16/6/2010
Safe Operation of Biological Safety Cabinet
(Adopted from OSHE/SOP/BS/04)
Page:
Page 1 of 5
Safety & Health
Laboratory (Location):
Cytokine biology Lab, MD9
Prepared/Review By
Approved By
Next Review Date
Oh Chu Yun
Dr. Leung Pui Lam Bernard
16/6/2013
* Review Date = Future date for the next revision (every 3yrs)
1.0 OBJECTIVE
The purpose of this guideline is to detail the safe operation of biological safety cabinets in
Department of Physiology laboratories to ensure adequate containment of biological materials.
2.0 SCOPE
The Biological Safety Cabinets (BSC) currently being used in the Department of Physiology.
3.0 RESPONSIBILITIES
3.1 HOD/PI
The HOD/PI has overall responsibility for ensuring staff under their supervision have undergone
safety training on the use of BSC.
3.2 Designated Person
There shall be a designated person to oversee the correct operation and maintenance of the
BSC. This person shall:
a. Periodically inspect the BSC to ensure its operational performance.
b. Arrange for the yearly safety certification by a competent person and keep a copy of the
certification report for verification purposes.
c. Make necessary arrangements for repair works of the BSC.
d. Report to the Director/HOD/PI unsafe practices by BSC users.
3.3 BSC Users
a. BSC users shall attend appropriate training on the hazards and safe use of the BSC.
b. BSC users shall report any injuries, defects or breakdowns to their supervisor or the
designation person.
Department of Physiology
Procedure No:
PHY/SOP/EQ03
Revision No:
001
Title:
Effective Date :
16/6/2010
Safe Operation of Biological Safety Cabinet
(Adopted from OSHE/SOP/BS/04)
Page:
Page 2 of 5
Safety & Health
Laboratory (Location):
Cytokine biology Lab, MD9
4.0 DEFINITION
a. Biological Safety Cabinet (BSC): Air flow controlled hoods designed to protect the
operator, the laboratory environment and work materials from exposure to infectious
aerosols and splashes that may be generated when manipulating materials
containing infectious agents, such as primary cultures, stocks and diagnostic
specimens.
b. High Efficiency Particulate Air (HEPA): Filter that traps 99.97% of particles of 0.3
um in diameter and 99.99% of particles of greater size. Thus capturing all infectious
agents and ensure only microbe free air is exhausted from the cabinet.
c. Class I cabinets protect personnel and the environment, but not research materials.
They provide an inward flow of unfiltered air, similar to a chemical fume hood, which
protects the worker from the material in the cabinet. The environment is protected by
HEPA filtration of the exhaust air before it is discharged into the laboratory or to the
outside via the building exhaust.
d. Class II (Types A, B1, B2, and B3) biological safety cabinets provide personnel,
environment, and product protection. Air is drawn around the operator into the front
grille of the cabinet, which provides personnel protection. In addition, the downward
laminar flow of HEPA filtered air within the cabinet provides product protection by
minimizing the chance of cross-contamination along the work surface of the cabinet.
Because cabinet air passes through the exhaust HEPA filter, it is contaminant-free
(environment protection), and may be circulated back into the laboratory (Type A) or
ducted out of the building (Type B).
e. Class III cabinets (sometimes called Class III glove boxes) were designed for work
with infectious agents that require Biosafety Level 4 containment, and provide
maximum protection to the environment and the worker. The cabinet is gas-tight with
a non-opening view window, and has rubber gloves attached to ports in the cabinet
that allow for manipulation of materials in the cabinet. Air is filtered through one
HEPA filter as it enters the cabinet, and through 2 HEPA filters before it is exhausted
to the outdoors. This type of cabinet provides the highest level of product,
environmental, and personnel protection.
f. Laminar flow "clean air benches" are not BSCs. They discharge a laminar flow of
HEPA-filtered air from top to bottom or across the work surface and toward the user,
providing only product protection.
g. They can be used for certain clean activities, such as dust-free assembly of sterile
equipment or electronic devices. However, they should never be used when handling
cell culture materials or potentially infectious materials, or as a substitute for a
biological safety cabinet in research laboratories. (Note: The choice of BSC would be
decided from a risk assessment as stipulated in procedure on Risk Assessment has
been performed.)
Department of Physiology
Procedure No:
PHY/SOP/EQ03
Revision No:
001
Title:
Effective Date :
16/6/2010
Safe Operation of Biological Safety Cabinet
(Adopted from OSHE/SOP/BS/04)
Page:
Page 3 of 5
Safety & Health
Laboratory (Location):
Cytokine biology Lab, MD9
5.0 PROCEDURES
5.1 Preparation & material placement
a. Read the Material Safety Data Sheets for materials being used in a hood. Note any
precautions regarding the use of the chemical or microorganisms in the BSC.
b. Turn on the fluorescent light and cabinet fan 15 minutes before beginning work.
c. Check the air intake and exhaust grilles for obstructions, and check the pressure gauge
reading (indicates HEPA filter loading, if you do not know the acceptable reading is for
the cabinet, ask the certifier).
d. If the cabinet is equipped with an alarm, test the alarm and switch it to the “ON” position.
e. Confirm inward air flow by holding a tissue at the middle of the edge of the viewing panel
and ensuring it is drawn in.
f. Decontaminate the cabinet surface and surface-decontaminate all materials to be placed
inside the BSC with 70% alcohol or preferably some non-flammable disinfectant.
g. Work may be performed on disinfectant-soaked absorbent towels to capture splatters
and splashes.
h. Bulky items, such as biohazard bags, discard pipette trays and suction collection flasks
should be placed to one side of the interior of the cabinet.
i. Aerosol generating equipment (e.g. mixers, centrifuges, etc) should be placed towards
the rear of the cabinet.
j. Keep the work area of the BSC free of unnecessary equipment or supplies. Clutter
inside the BSC may impede proper air flow and the level of protection provided. Also,
keep the front and rear grilles clear.
k. Wear double gloves to minimize skin contact. If the outer gloves are contaminated,
discard them and put on a fresh pair. Gloves should be pulled over the wrists of the
gown rather than worn inside.
l. Generally front opening gowns should be worn for Biosafety level 1 work and back
opening gowns for Biosafety level 2 work.*
m. Masks and safety glasses may be required for some procedures.*
*The nature of the Personal Protective Equipment (PPE) worn would vary according to
the findings obtained from the biological risk assessment.
5.2 Operation
a. Active work should flow from clean to contaminated areas across the work surface.
b. Arms should be moved in and out slowly, perpendicular to the front opening to minimize
disruption of the air curtain and laminar flow. Manipulations of materials within BSCs
should be delayed for about 1 min after placing hands and arms inside to allow the
cabinet to adjust and to “air sweep” the surface of the hands and arms.
Department of Physiology
Procedure No:
PHY/SOP/EQ03
Revision No:
001
Title:
Effective Date :
16/6/2010
Safe Operation of Biological Safety Cabinet
(Adopted from OSHE/SOP/BS/04)
Page:
Page 4 of 5
Safety & Health
Laboratory (Location):
Cytokine biology Lab, MD9
c. Work as far to the back (beyond the air split) of the BSC workspace as possible, but
within comfortable reach.
d. Always use mechanical pipetting aids. No mouth pipetting is allowed
e. Heat sources such as Bunsen burners are strictly prohibited inside the BSCs as they
significantly disrupt the laminar flow of air.
f. To sterilize bacteriological loops, microburners or electric “furnaces” shall be used.
g. Do not work in a BSC while a warning light or alarm is signaling.
h. Locate liquid waste traps inside cabinet and use a hydrophobic filter to protect the
vacuum line. If traps must be located on the floor, place them in a secondary container
(such as a cardboard box) to prevent breakage.
5.3 Spillage
a. If there is a spill of biological material during use, surface decontaminate all objects in
the cabinet; disinfect the working area of the cabinet while it is still in operation (do not
turn the cabinet off). (Refer to SOP on Biological Spill Response - CBL/SOP/02)
b. If spillage occurs outside the cabinet, involve your supervisor immediately to activate
your spill control/response group.
5.4 Cleaning and disinfection
a. When work is completed, all equipment and supplies from the cabinet should be surfacedecontaminated and removed from the cabinet.
b. The interior surfaces should also be wiped with an appropriate disinfectant that would kill
any microorganisms that could be found in the cabinet. Corrosive chemicals such as
sodium hypochlorite should be avoided, but if used, should be followed with a wipe down
of sterile water.
c. Allow the cabinet to run for 15 minutes.
5.5 Decontamination
a. BSC must be decontaminated before filter changes and before being moved.
b. The most common decontamination method is by fumigation with formaldehyde gas.
BSC decontamination should be performed by a qualified professional.
5.6 Other considerations
a. All repairs to the BSC should be done by a qualified technician. Any malfunction in the
operation of the BSC should be reported and repaired before the BSC is used again.
b. The BSC should be positioned in an isolated corner to minimize disruption of the air
intake arising from traffic around the biosafety cabinet or drafts from doors and air
conditioning. There should be at least a 30 cm clearance provided behind and on each
side of the cabinet to allow easy access for maintenance. A clearance of 30 to 35 cm
above the cabinet may be required to provide for accurate air velocity measurement
across the exhaust filter and for exhaust filter changes.
Department of Physiology
Procedure No:
PHY/SOP/EQ03
Revision No:
001
Title:
Effective Date :
16/6/2010
Safe Operation of Biological Safety Cabinet
(Adopted from OSHE/SOP/BS/04)
Page:
Page 5 of 5
Safety & Health
Laboratory (Location):
Cytokine biology Lab, MD9
c. BSC must meet the requirements of any international certification bodies (e.g. NSF,
AS/NZ etc.). For BSC II Type B, an alarm that is audible at the cabinet should be
provided to indicate loss of exhaust flow from the building exhaust system. The cabinet
should also be interlocked with the building exhaust system to prevent pressurization of
the cabinet in the event of building exhaust fan failure.
d. The BSC must be subjected to a yearly certification by a competent/qualified
professional to an international standard such as the Canadian Standards Association
(CSA) Z316.3-95. Recertification is required each time the BSC is repaired or relocated.
6.0 RECORDS
a. A copy of the certification report must be kept in a file by the BSC owner for verification
purposes.
b. A label indicating the date of certification, the date of the next certification, what standard
tests were performed, and the name of the certifier should be affixed to the exterior of
the cabinet.
7.0 REFERENCES
a. National Sanitation Foundation (NSF)/ANS 49 -2002 standard
b. CBL/SOP/02– Biological Spill Response
c. CBL/SOP/GS/07– Selection of PPE
8.0 APPENDICES
Nil