NuAire LabGard NU-560-400, Operation & Maintenance Manual

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OM0295
Rev 2 September 2020 Page 34 of 103
6.2 Operating Guidelines
The intent herein is to present general operational guidelines that will aid in the use of the Laminar Flow Biosafety Cabinet
(LFBSC) to control airborne contaminants of low to moderate risk as stated in Technical Report No. FPS 56500000001
prepared by Dow Chemical U.S.A. for the National Cancer Institute, May 1, 1972.
Procedure protocols defined in terms of the barrier or control concepts unique to LFBSC must be developed in order to
obtain a maximum potential for safety and protection. The pre-planning necessary to develop these protocols is based on
several fundamental considerations, each of which will contribute to optimum benefits from the equipment:
a. Know your "Safe Work Area"
b. Minimize disruption of "air curtain"
c. Minimize room activity
d. Utilize unidirectional airflow
e. Employ aseptic techniques
6.2.1 Know Your "Safe Working Area"
The LFBSC safe working area is basically the worktray or depressed area. All work should be performed on or
above the worktray. The area on or above the front grill is a non-safe working area.
NOTE: It is important to maintain an air gap on both sides of the worktray before fastening in place.
The work tray as being part of the cabinet has been designed to load up to 100 lbs. (45.4 kg.) of work
materials. Any additional loading should be evaluated by appropriate safety personnel.
6.2.2 Minimize Penetration of "Air Curtain"
The minimum number of items necessary should be placed into the cabinet to prevent overloading, but the work
should also be planned to minimize the number of times an operator's hands and arms must enter and leave the
air curtain at the open face. The ideal situation is to have everything needed for the complete procedure placed in
the hood before starting, so that nothing need pass in or out through the air barrier at the face until the procedure
is completed. This is especially important in working with moderate risk agents.
Unnecessary rising of the hands inside the cabinet above the level of the work opening should be avoided. This
presents an inclined plane from hands to elbows along which the downflow of air may run to, and possibly out, the
open face.
NOTE: When working with agents of lower risk, it is not as important for all materials to be placed in the
cabinet before starting, or for the procedure to be completely finished before materials are removed.
Also, the time period for a cabinet may be continued over a more extended period during which entries
and withdrawals from the cabinet may be made.
6.2.3 Minimize Room Activity
Activity in the room itself should be held to a minimum. Unnecessary activity may create disruptive air currents as
well as interfere with the work of the operator. A person walking past the front of a cabinet can cause draft
velocities up to 175 fpm (.89 m/s), which are sufficient to disrupt the air balance of the laminar flow cabinet.
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