This document provides tips for safely working in a biological safety cabinet. Some key points include: - Know how the airflow works to provide proper protection and avoid disrupting the air curtain. - Work at the proper sash height and never cover the air grill to maintain airflow integrity. - Minimize rapid movements and other activities that could disrupt the protective air barrier. - Follow good techniques to reduce splatters and aerosols and minimize cross-contamination risks.

1. TIPS FOR WORKING
SAFELY IN YOUR
BIOLOGICAL SAFETY CABINET
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2. KNOW YOUR AIRFLOW
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Biological Safety Cabinets
provide personnel, product
and environmental protection
through the use of HEPA
filtered air. Knowing how the
air is passed through the
cabinet an essential piece of
the puzzle to know.

3. WORK AT THE PROPER SASH LEVEL
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Proper airflows are reached by
a certifier measuring air speed
on an annual basis (or more) to
put a stamp of approval that
the cabinet is fully operation
to provide personnel, product,
and environmental protection.

4. NEVER COVER THE AIR GRILL
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Covering the air grill at the front of
the cabinet compromises airflow
integrity. Blocking the grill can cause
laboratory air to enter the work zone
or even work zone air to enter the
laboratory environment.
PS. This goes for your elbows and
arms as well. NuAire offers elbow rest
accessories to avoid this occurrence.

5. MINIMIZE MOVEMENT
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The rapid movement of a worker’s
arms in a sweeping motion into and
out of the cabinet will disrupt the air
curtain and may compromise the
partial barrier containment provided
by the BSC.
Moving arms in and out slowly,
perpendicular to the face opening of
the cabinet, will reduce this risk.
Other personnel activities in the
room (e.g., rapid movement,
open/closing room doors, etc.) may
also disrupt the cabinet air barrier.

6. REDUCE SPLATTER
Many common procedures conducted in Biological Safety Cabinets may create splatter or
aerosols. Good microbiological techniques should always be used when working in a
Biological Safety Cabinet to minimize this potential.
For example, techniques to reduces platter and aerosol generation will minimize the-potential
for personnel exposure to infectious materials manipulated within the cabinet.
Class II cabinets are designed so that horizontally nebulized spores will be captured by the
downward flowing cabinet air within fourteen inches (35 cm) of travel. As a general rule of
thumb, keeping clean materials at least twelve inches (31 cm) away from aerosol-generating
activities will minimize the potential for cross-contamination.
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7. KNOW YOUR WORK AREA
The middle third of the work surface
is the ideal area to be used. All
operations should be performed at
least 4 inches from the front grille on
the work surface.
Materials or equipment placed
inside the cabinet may cause
disruption to the airflow, resulting in
turbulence, possible cross-contamination,
and/or breach of
containment.
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8. CLEAN WORK AREA DIRTY
WORK FROM CLEAN TO CONTAMINATED
Active work should flow from the clean to contaminated area across the work surface. Materials
and supplies should be placed in such a way as to limit the movement of “dirty” items over
“clean” ones.
Maintain proper balance of materials from left to right in order to prevent an airflow imbalance
within the work zone. 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. All materials should
be placed as far back in the cabinet as practical, toward the rear edge of the work surface and
away from the front grille of the cabinet. Similarly, aerosol-generating equipment (e.g., vortex
mixers, tabletop centrifuges) should be placed toward the rear of the cabinet to take advantage
of the air split.
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9. WORKING WITH TUBES/BOTTLES
Open tubes or bottles
should NOT be held in a
vertical position. Bottle
or tube caps should not
be placed on the
toweling. Items should
be recapped or covered
as soon as possible.
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10. WORKING WITH PETRI DISHES
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Investigators
working with Petri
dishes and tissue
culture plates should
hold the lid above
the open sterile
surface to minimize
direct impaction of
downward air.

11. WORKING WITH ASPIRATOR BOTTLES OR
SUCTION FLASKS
Aspirator bottles or suction flasks should be connected to an overflow collection flask containing
appropriate disinfectant, and to an in-line HEPA or equivalent filter.
This combination will provide protection to the central building vacuum system or vacuum
pump, as well as to the personnel who service this equipment. Inactivation of aspirated
materials can be accomplished by placing sufficient chemical decontamination solution into the
flask to kill the microorganisms as they are collected. Once inactivation occurs, liquid materials
can be disposed of appropriately as noninfectious waste.
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12. WATCH WHERE YOU ARE WALKING
You don’t have to be working in the biological safety
cabinet to cause airflow disruptions and the potential
for contamination. By walking too quickly pass a
biological safety cabinet you disturb the protective air
curtain at the front of the cabinet. This disruption can
lead to contaminated work zone air to enter the
laboratory environment or even contaminated
laboratory air to enter sterile work zone.
Remember to slow down and avoid walking
too close. A good idea might be to create a
working / no walking zone in front of the
cabinet with either tape or paint.
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13. POSITIONING YOURSELF WHEN WORKING
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Working in a biological safety cabinet requires
repetitive work. Ergonomics plays a huge role
during your time in front of a biological safety
cabinet.
A good laboratory chair helps a ton. Remember 90
degree angles can help prevent work place injuries.
A straight upright back can save you from pain in
the long run. Over extending your arms can cause
stress on your shoulders and back.
Remember to keep straight wrists and think about
becoming ambidextrous with your pipette to give
your tendons a reset once in a while or even try
different types of pipettes in one sitting to work
different muscles and tendons.
Remember the way you sit and operate in a
Biological Safety Cabinet not only can have an
effect on your wellbeing but could cause work
mishaps when your concentrating more on a sharp
pain than where you might be sticking a needle.
90° Seating Angle 90° Knee Angle Foot Rest Straight Wrists

14. CONTROL PANEL CHECK
(OPTIMAL AIRFLOW/DIFFERENTIAL PRESSURE AND ALARM RESPONSE)
Personnel, product and environmental protection are what a Biological Safety Cabinet provides. This is down through
airflows, a motor and HEPA filters. If a motor is not running properly or a HEPA filter has reached its maximum life a
Biological Safety Cabinet can compromise your three protection areas and destroy your work or even worse if
someone becomes sick.
A majority of Biological Safety Cabinets will feature some type of pressure or airflow monitor. Half of those Biological
Safety Cabinets will have some type of alarm to notify you airflow is NOT optimal. Others will feature a mini or mage-helic
gauge to monitor pressure. These models do not feature an alarm so a daily safety check will have to be made
before you begin work.
A good idea would be to place this at the top of your standard operating procedure or even place a sticker (if allowed)
around the monitor saying “CHECK ME PLEASE”.
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