2. We all know what is a lab!
• A place where our safety is at risk
• A place where precautions are obligatory and extremely
necessary
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3. One of the most equipments used for
protection are Biological Safety
Cabinets
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4. What is a Biological Safety Cabinet?
Biological safety cabinet or microbiological
safety cabinet is an enclosed, ventilated
laboratory workspace for safely working with
materials contaminated with (or potentially
contaminated with) pathogens requiring a
defined biosafety level
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5. Biological safety cabinets (BSCs) are designed to protect:
• the operator
• the laboratory environment
• 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
What are designed for?
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6. Selection of Biological Safety Cabinets
A BSC should be selected primarily in accordance with the
type of protection needed:
• product protection
• personnel protection
against Risk Group 1–4 microorganisms; personnel protection
against exposure to radionuclides and volatile toxic chemicals;
or a combination of these
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8. HEPA Filters
• HEPA filter = is a High Efficiency
Particulate Air filter
• Filters, whether for an air purifier
or other implementation, come
with many benefits
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9. How do HEPA filters work?
• The HEPA filter traps 99.97% of particles of 0.3
𝜇m in diameter and 99.99% of particles of
greater or smaller size
• This enables the HEPA filter to effectively trap
all known infectious agents and ensure that only
microbe-free exhaust air is discharged from the
cabinet
• It provides products and personal protection
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10. BSC Class I
• Class I cabinets provide worker and environmental protection, but no
product protection
• It is used for BSL 1-3
• Air drawn inside is not HEPA filtered
• The exhausted air is HEPA filtered ( environmental protection)
• Class I cabinets may be used to enclose equipment or procedures with a
potential to generate aerosols
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12. BSC Class II
• Class II biological safety cabinets provide personnel, environmental and
product protection
• It is used for BSL 1-3
• Both room air and interior cabinet air are drawn into a front grille creating
an air barrier that provides personnel protection
• In addition, downward laminar flow of HEPA-filtered air provides product
protection. Air exhaust passes through a certified exhaust HEPA filter and
may be recirculated back into the laboratory or exhausted out of the
building 12/28
14. Type (Class)
Worker
Protection
Product
Protection
Environment
Protection
Volatile
Chemicals
Application
II, A1
Yes Yes Yes No
Cell culture and infectious material procedures
that do not include the use of volatile chemicals.
II, A2
Yes Yes Yes
Yes (minute
amounts)**
Same as Type A but exhausted to outside. Minute
quantities of hazardous chemicals may be used.
II, B1 Yes Yes Yes
Yes (minute
amounts)**
Must be hard-ducted to exterior exhaust. Same
procedures as Type II,A but manipulations of
minute quantities of hazardous chemicals used
with in vitro biological systems can be done.
II, B2 Yes Yes Yes
Yes (small
amounts)
Cabinet has total-exhaust, no air is recirculated.
This cabinet provides simultaneous primary
biological and chemical containment. Care must
be given as some chemicals can damage the
filters or gaskets.
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Table 1. Characteristics of the types of BSC Class II
15. BSC Class III
• Class III BSC, is fully enclosed to provide operator protection
• It provides personal , environmental and product protection and
used for BSLVI
• Product enter and exited through double door autoclave
• Class III is a gloveboxes, as work is done through rubber gloves
and seen through the sash
• Air entered and exited is HEPA-filtered
• Between the exited HEPA filters there is a negative alarm for
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17. • “Thimble” or “Canopy
Hood” is placed in cabinet
exhaust housing it sucks the
cabinet exhaust air into
building exhaust ducts
• Small opening found with
D=2.5cm that sucked the
room air into the building
exhaust system as well
• Hard-ducted is without any
any openings to the building
building exhaust system
BSC Air
ConnectionBSC Face
Velocity
(m/s)
Air flow Exhaust system
Recirculated Exhausted
Class I 0.36 0 100 Hard duct
Class II A1 0.38-0.51 70 30 Exhaust to room
or thimble
connection
Class II A2 0.51 70 30 Exhaust to room
or thimble
connection
Class IIB1 0.51 30 70 Hard duct
Class II B2 0.51 0 100 Hard duct
Class III not
applicable
0 100 Hard duct
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18. Sum up
BSC levels BSL LEVEL
OF
AGENT
USED
Type of Protection NON-VOLITILE TOXIC
CHEMICALS &
RADIONUCLIDES
VOLITILE TOXIC
CHEMICALS &
RADIONUCLIDES
Worker
protection
Environmental
protection
Product
protection
BSCI 1-3 Yes Yes No YES No
BSCII A1 1-3 Yes Yes Yes YES ( minute volatile) No
BSCII A2 1-3 Yes Yes Yes YES Minute amount
BSCII BI 1-3 Yes Yes Yes YES Minute Amount
BSCII BII 1-3 Yes Yes Yes YES Small amount
BSCIII 4 Yes Yes Yes YES Small amount
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Table3. Comparison Between all Bio-Safety Cabinets and Their Sum Up
19. Using Biological Safety Cabinets in
the laboratory
Where is the best location within the laboratory for a
biological safety cabinet?
The ideal location is a dead-end corner of the laboratory, away from
personnel traffic, vents, doors, windows and other sources of
disruptive air currentsAlso:
• Air current may be disrupted by walking close to it, open
windows or doors
• 30cm behind & on each side should be provided to allow access
• 30-35cm above for accurate air velocity, across exhaust filter
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20. • If cabinets aren’t used properly,
no benefits from them :
1. Arms should be moved in &
out slowly & perpendicular to
the front opening
2. Manipulations of materials
with in BSC should be delayed
for about 1 minute after
placing in order to allow “air
sweep”
Operators
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21. • Front intake grill of class II must
not be blocked
• Materials should be
decontaminated with 70 %
alcohol
• It should be performed on
disinfectant-soaked towels to
capture splashes
• Materials should be placed
towards the rear edge where
aerosoid generator equipment
(mixers, centrifuges) should be
placed
Material
Placement
• Most operations are designed to
permit 24h/day
• Class II A1& A2 can be turned of
when not in use
• Class II B1& B2 should be turned
on before & after 5 min at least in
order to “purge’’
• Any problem should be reported &
repaired before each use
Operations & Maintenance
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22. Ultra-violet lights
• If they are present, they should be cleaned every week& light intensity
should be
checked
Open flames
• Should be avoided in order to protect our work & out to disrupt air flow patte
Spills:
• When spills occurs:
1. Clean up immediately
2. Disinfect or place in autoclave everything that come in contact with the
spilled agents
N.B.We should read laboratory protocol for handling spills22/28
23. Cleaning & Disinfection
• All items with in BSC
should be surface
decontaminated &
removed from the cabinet
when work is done
• Interior Surface of cabinet
must be decontaminated
before & after usage with
a wiped disinfectant
• A second wiping with
sterile water is needed
with a bleach or 70%
alcohol 23/28
24. • Wear PP cloth
• Coats for Biosafety Level 1 & 2
• Solid front , back closing laboratory provides better protection for level
3& 4
Personal Protective Equipment
(PPE)
• Sash Alarm:
Found in cabinets with sliding sashes, signifies when sash is moved to
improper position
• Air flow Alarm:
Signifies when disruption in air flow, danger for operator & product, when
sound goes out , work should be ceased & notify for the supervisor
Alarm
s
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25. Safety equipments
Safety equipments are designed
to eliminate or reduce certain
hazards and briefly outline the
safety features
Example, they are used for
personal protective body and
clothing or from aerosols as an
important source of infection
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26. Personal protective equipment and clothing
• Personal protective equipment
are considered as double
protection while using
biological safety cabinets
Note : Before leaving the
laboratory, protective clothing
should be removed, and hands
should be washed
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