Biological Safety Cabinet_ TB 07-01_V1.0.doc
Document type: SOP
Document code: TB 07-01
BIOLOGICAL SAFETY CABINET USE AND
MAINTENANCE
Confidentiality: none
TABLE OF CONTENTS
1.
PURPOSE................................................................................................................................ 2
2.
SCOPE ..................................................................................................................................... 2
3.
RESPONSIBILITIES................................................................................................................ 2
4.
CROSS-REFERENCES .......................................................................................................... 2
5.
PROCEDURES ........................................................................................................................ 2
5.1. Procedures before working in the safety cabinet .............................................................................. 2
5.2. Working in the biological safety cabinet ............................................................................................ 3
5.3. Procedure after working in the safety cabinet................................................................................... 3
5.4. Daily maintenance .............................................................................................................................. 4
5.5. Weekly maintenance .......................................................................................................................... 5
5.6. Servicing ............................................................................................................................................. 5
5.6.1
Decontamination using potassium permanganate/formaldehyde .........................................5
5.7. Records keeping ................................................................................................................................. 6
5.8. Action in case of interruption of power supply.................................................................................. 6
6.
REFERENCES ........................................................................................................................ 6
7.
CHANGE HISTORY ................................................................................................................ 6
This SOP template has been developed by FIND for adaptation and use in TB laboratories
Release date: ddMMMyy
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Biological Safety Cabinet_TB 07-01_V1.0.doc
1.
PURPOSE
This SOP describes the use and maintenance of the Biological Safety Cabinets in the __________ TB
Laboratory. Biological Safety Cabinets (Class II) afford protection for experiments, personnel and
environment. The correct use and maintenance of Biological Safety Cabinets is important for correct
functioning. Cabinets must be regularly maintained, and records of vertical air pressure, servicing, and
repairs kept. However, no cabinet can replace good aseptic and procedural control techniques.
2.
SCOPE
This SOP covers all procedures involving potentially infectious specimens or samples performed in the
__________ TB Laboratory.
3.
RESPONSIBILITIES
All staff members working in the __________ TB Laboratory are responsible for the implementation of
this operating procedure. Any malfunctions of the Biological Safety Cabinets must be reported
immediately to the Head of the Laboratory, and work therein halted until corrective action is taken.
All users of this procedure who do not understand it or are unable to carry it out as described are
responsible for seeking advice from their supervisor.
4.
CROSS-REFERENCES
See:
Document Matrix_TB 01-01_V1.0.doc
Location:
5.
PROCEDURES
5.1. Procedures before working in the safety cabinet

If the unit has not been left running continuously, press the blower on/off switch below the switch.
The indicator light will light. The unit should be left running for a minimum of 15 minutes before
starting work.

Note: It is recommended to keep the air switched on permanently where possible.

Check and record the vertical air pressure in the Biological Safety Cabinet and Air System
Maintenance Logbook. It should be consistent with the last reading.
Use:
BSC and Air System Maintenance_form.doc
Location:

Turn on the fluorescent light. The fluorescent light will not operate until the UV light is turned off.

Check to determine that the drain valve is in the closed position.

Wipe down the interior area of the cabinet with suitable mycobactericidal disinfectant.
See:
Laboratory Cleaning and Maintenance_TB 02-04_V1.0.doc
Location:
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Biological Safety Cabinet_TB 07-01_V1.0.doc

Place all materials to be used for the next procedure inside the cabinet on the solid work surface.
Disinfect the exterior of these materials prior to placing them on the work surface.

A disposable bag and disinfectant must be available before work is started and should be placed
to one side of the work area.

Everything required (and nothing more) should be placed in the cabinet before beginning your
work so that nothing passes in and out through the air barrier, until the procedure is completed.

Implements should be arranged in the cabinet’s work area in logical order so that the clean and
dirty materials are be segregated, preferably on opposite sides of the work area.

Blocking the front and rear perforated grills must be avoided.

After equipment is in place inside the cabinet, adjust the sliding viewscreen so it is open no higher
than the correct opening height. An alarm will signal if you are not at the cabinet designed opening
height. This is important to maintain proper airflow.

After the cabinet has run for at least three minutes with the window in the proper position, you are
ready to begin.
5.2. Working in the biological safety cabinet

Equipment taken into the cabinet should be kept to a minimum. However the worker should avoid
undue disruption of the airflow by repeatedly bringing equipment or reagents in and out of the
cabinet.

Work should be delayed for approximately one minute after bringing hands into the cabinet to
allow the airflow to equilibrate.

Perform all work in the central area of the cabinet. Blocking of air vents and the front and the rear
grills must be avoided at all times. Do not work too close to the front of the cabinet. This can
cause exposure of the operator as well as potential for contamination.

Work with a limited number of slow movements.

Because opening and closing doors in the laboratory causes air disturbance which might interfere
with cabinet airflow, this kind of activity should be kept to a minimum while the cabinet is in use.
Personnel should avoid walking in front of the cabinet while it is in use so as not to disrupt the
airflow.

All items to be discarded must be discarded in the cabinet to avoid moving hands in and out of the
work area.

Paperwork should never be placed inside the cabinet.

Bunsen burners must not be used inside the cabinet as the heat may disrupt the airflow and may
damage the filters.

Never operate the cabinet while the viewscreen alarm indicator is on. Adjust the height of your
chair to keep the operating position of the sash optimal.
5.3. Procedure after working in the safety cabinet

After a procedure has been completed, all biological waste material must be placed in the
disposable bag in the cabinet and all opened vials/ bottles/containers should be closed.
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Biological Safety Cabinet_TB 07-01_V1.0.doc

The cabinet should then be allowed to run for at least three minutes with no activity so that the
airborne contaminants will be removed from the work area.

Decontaminate and remove all equipment from the cabinet and any other items that may inhibit
the cleaning of the entire work surface (e.g. plates, vortexes etc).

The liquid discard bins need not to be removed every day, but the outer surfaces must be
thoroughly disinfected.

Decontaminate of the interior surface of the cabinet. Wipe down the interior walls with appropriate
disinfectant. Flood and spread across the work surface the disinfectant then swab it up using
absorbent paper towel.

Paper towel and gloves must be discarded in the disposable bag in the cabinet. The bag must be
sealed while in the cabinet and then be discarded in the biohazard waste bin.
5.4. Daily maintenance

Check and record the vertical air pressure in the Biological Safety Cabinet and Air System
Maintenance Logbook (see above for location).

It should be consistent with the last reading.

If a drop in vertical air pressure is noted an Equipment Failure Report must be completed and the
service representatives must be called out.

Under no circumstances must work be performed in the cabinet if the vertical air pressure
is not correct. An Equipment Failure Notice must be placed on the cabinet indicating that work is
prohibited in the cabinet.
Use:
Equipment Failure Notice_form.doc
Equipment Failure Report_form.doc
Location:

At the end of the working day, all biological material must be placed in a disposable bag in the
cabinet.

Decontaminate and remove all equipment from the cabinet and any other items that may inhibit
the cleaning of the entire work surface (e.g. plates, vortexes etc).

The liquid discard bins need not to be removed every day, but the outer surfaces must be
thoroughly disinfected.

Decontaminate of the interior surface of the cabinet. Wipe down the interior walls with appropriate
disinfectant. Flood and spread across the work surface the disinfectant then swab it up using
absorbent paper towel.

Paper towel and gloves must be discarded in the disposable bag in the cabinet. The must be
sealed while in the cabinet and then be discarded in the biohazard waste bin.

The outer surface of the glass panel of the cabinet must be wiped down with the disinfectant.

At the end of the working day the cabinet lights must be switched off.

At the end of the day record cleaning in the Laboratory Cleaning and Maintenance Logbook
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Biological Safety Cabinet_TB 07-01_V1.0.doc
Use:
Laboratory Cleaning and Maintenance Logbook_form.xls
Location:
5.5. Weekly maintenance
In addition to daily maintenance, the following procedures must be performed on a weekly basis:

On the last working day of the week, the entire cabinet should be disinfected using suitable
mycobactericidal disinfectant. The procedures detailed in sections 4.2 – 4.4. must be followed.

Following these procedures, the bottom tray should be removed and decontaminated using
suitable mycobactericidal disinfectant.

All the surfaces of the cabinet, including the bottom tray, should be wiped down with 70% alcohol
following disinfection with mycobactericidal disinfectant, and any residual absorbent paper or
cotton wool should be removed.

The glass panel should not be wiped with 70% alcohol as it may spoil it. Disinfection should be
followed by water in this case.

Record cleaning in the Laboratory Cleaning and Maintenance Logbook (see above for location).
5.6. Servicing

Cabinets must be serviced bi-annually as per the manufacturer’s instructions.

The evening prior servicing, the cabinets must be decontaminated.
5.6.1
Decontamination using potassium permanganate/formaldehyde

For each cabinet, weigh 60g of potassium permanganate and place this in a large plastic bucket.

Measure out 75ml of water and 75ml of 40% formaldehyde into separate bottles.

Place the bucket containing the potassium permanganate in the cabinet.

Close the front of the cabinet with the cabinet shield provided, leaving only the small access door
open.

Seal the exhaust filter on the top of the cabinet with the plates provided.

Place the bottles of water and formaldehyde in the cabinet.

At the end of the day, pour the water and then the formaldehyde into the bucket.

Close the access door on the cabinet shield and seal.

Note: the gas produced is highly toxic, and the room should be evacuated as soon as possible.

Allow the formaldehyde a resident time of 12 hours, preferably overnight.

Remove the cabinet shield the following morning.

Remove the bucket and bottles from the cabinet, and wash them in running water.

Clean the surface of the cabinet with suitable mycobactericidal disinfectant.

When cleaning up you may find residual formaldehyde (white powder) on the surfaces. To remove
this use ammonia in warm water, wear gloves and wipe down the affected surface.
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Biological Safety Cabinet_TB 07-01_V1.0.doc
5.7. Records keeping
Records of the vertical air pressure, servicing, and repairs should be kept, and filed in the Equipment
Maintenance File. In the event of any defect being identified by the service representatives during the
bi-annual service, this must be rectified, and the cabinet re-validated, prior to initiating any further work
in the cabinet.
Records of the service must be kept in the Equipment Maintenance File
Use:
Equipment Maintenance File_form.doc
Location:
5.8. Action in case of interruption of power supply
Both Biological Safety Cabinets are attached to emergency power source. In the event of a power
failure, the cabinets will automatically connect to the emergency generator.
6.
REFERENCES
Kruse, RH; Puckett, WH; Richardson JH. 1991. Biological safety cabinetry. Clinical Microbiology
Reviews 4, 207-241.
World Health Organization. Laboratory biosafety manual. Third edition. 2004.
WHO/CDS/CSR/LYO2004.11
The Baker Company Operator’s Manual. Biological Safety Cabinets.
7.
CHANGE HISTORY
New version #
/ date
Old version #
/ date
No. of
changes
Description of changes
Source of
change request
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