1. Biological Safety
Cabinets(BSCs)
Sudheesh N
Research Assistant
Department of Virus Research

2. Objectives
 Identify and distinguish the various types
of open front biological safety cabinets
 Describe how to effectively and safely use
biological safety cabinets
 HEPA and ULPA
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3. HEPA Filters
 High Efficiency Particulate Air
 Filters particles at 99.97% efficiency at 0.3
microns
– larger and smaller particles are filtered at higher
efficiency
 Gases and vapors are not removed from the
air stream by HEPA filtration
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4. HEPA Filter
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5. 3 ways to capture the Particle
 Diffusion
 Interception
 Inertial Impaction
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6. ULPA
 Ultra Low Penetration Air
 Filters particles at 99.9995% efficient in
removing particles 0.12 µm and larger
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7. Biological Safety Cabinets
 Used to provide containment of infectious
splashes or aerosols generated-Primary
Biological
Containment
Safety
Cabinet
Class
III
Class I
Class
II
Type A1
Type A2
Type B1
Type B2
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8. Class I BSC
A. front opening
B. sash
C. exhaust HEPA
D. exhaust plenum
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9. Class II BSC
 Class II Type A1
• 70% re circulated air; 30 % exhausted into the room
• 75 fpm intake
Class II BSC
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10. Class II BSC
 Class II Type A2
•70% re circulated air; 30 % exhausted into the room
• 100 fpm intake
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11. Class II BSC
 Class II Type B1
• 40% re circulated air; 60 % exhausted
• 100 fpm intake
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12. Class II BSC
 Class II Type B2
• 0% re circulated air; 100 % exhausted
• 100 fpm intake
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13. Class III BSC
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14. Primary Containment- Conclusion
 Are not substitutes for good practice
 Provide only partial protection; aerosols
can escape from the cabinet, especially
when rapid motion occurs through the air
curtain
 Should be retested and recertified
annually and when the cabinet is moved
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