1. Tobias van Reenen ABCs of Biohazard Safety Cabinets
4/4/2019
ABCs of Biohazard Safety Cabinets
Biosafety Cabinets
Tobias van Reenen

2. Biohazard Safety Cabinets
4/4/2019
Biohazard Safety Cabinets
The terms Biological Safety Cabinet and Bio-Safety Cabinet are used to describe a variety of containment devices equipped with HEPA filter(s)
The terms should only be applied to those devices that meet the requirements of Class I, II, or III specifications.
Provide personnel or both personnel and product protection from bio hazardous materials.
BSC Classes based on their construction, airflow velocities and patterns, and their exhaust systems
Hepa Filters as already explained earlier by Mr van Reenen and one of the most important items in clean room and containment facilities with controlled environment.

3. CLASS I – BSC 100% Exhaust Inflow Velocity Critical. BSL 1 –3 Usage
4/4/2019
CLASS I – BSC
100% Exhaust
Inflow Velocity Critical.
BSL 1 –3 Usage
Personnel protection only
CDC/NIH recommends a glove-port
panel for use with small amounts of
radionuclide’s when exhausted
Typical uses today: Toxic powder weighing, necropsy
Maybe thimble or direct connected to an exhaust system.
Hepa Filters as already explained earlier by Mr van Reenen and one of the most important items in clean room and containment facilities with controlled environment.
Inflow velocities ext will be discussed later on.
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

4. CLASS II A2– BSC 30% Exhaust, 70% Re-circulate
4/4/2019
CLASS II A2– BSC
30% Exhaust, 70% Re-circulate
Negative Pressure Plenum
Inflow Velocity and Downward velocities
BSL 1 –3 Usage.
Personnel, Environment and Product Protection.
Minute amounts of volatile toxic chemicals and radionuclide's if canopy/thimble exhausted.
Typical uses today: Bacterial, Viral, Fungal, Parasitic, Arbor-viruses.
These Cabinets could be exhausted into the surrounding area Volatile chemicals and gasses can freely pass through hepa filters and as such when the cabinet is used for these applications it should be ducted out with a thimble connection .we will later on have a separate section on exhaust systems.There was an A 1 cabinet but these cabinets had positive pressure plenum and are no longer used as the risk of leakage trough these positive pressure plenums were to high and they are no longer manufactured.
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

5. CLASS II B2 – BSC 100% Exhaust Negative Pressure Plenum
4/4/2019
CLASS II B2 – BSC
100% Exhaust
Negative Pressure Plenum
Inflow Velocity 0.51m/sec minimum
BSL 1 –3 Usage.
Personnel Environment & Product protection.
Small amounts of volatile toxic chemicals and radionuclide’s
Must be directly connected to exhaust duct.
Must have interlocked internal blower with audible and visual alarm for exhaust failure.
Typical uses today: Bacterial, Viral, Fungal, Parasitic,
Arbor-viruses, Prion, Cytotoxics
Solid connection to the exhaust duct.
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

6. CLASS III – BSC 100% Exhaust, Glove Box type design.
4/4/2019
CLASS III – BSC
100% Exhaust, Glove Box type design.
Negative Pressure at 125Pa Minimum
Double HEPA Filter Exhaust recommended.
BSL 1-4
Personnel and Product Protection.
Small amounts of volatile toxic chemicals and radionuclides.
Must be direct connected with typical exhaust requirement being L/s at 125 Pa.
Must have negative pressure alarm for cabinet or
exhaust failure.
Typical uses today: Toxic Powders , BSL 4 Agents, BSL3 Agriculture.
Volatile potentially explosive. BSL 4 Marburg , Rift Valley ,Ebola VHF Viral hemorrhagic fevers . Toxic powders as Antrax which is a bacteria.
Double hepa filters exhaust with ability to leak test both hepa filters .No thimble connectios.
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

7. CABINET SELECTION Only the product protection required
4/4/2019
CABINET SELECTION
Only the product protection required
Laminar Flow Bench
Only Personnel protection
Fume Hood
Only Personnel and environmental protection
BSC I
Personnel, product, and environmental protection
BSCII +
Only material then a clean air bench will do. Technician and environment the class 1 will do and for all three a class II biohazard safety cabinet will do. Inflow will protect the operator , down flow will offer product protection and exhaust hepa filters will provide environmental protection.
Cabinets sold in South Africa have a homologations certificate issued by NCRS which will be in accordance with SABS VC8041 cabinets have been certified by an independent SANAS laboratory as complying with all the requirements as set out in the standard or cabinets with an EN Listing are sold locally with a sales permit issued by NCRS.
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

8. CABINET SELECTION BSC Class BSL Level of Agent Used
4/4/2019
CABINET SELECTION
BSC Class
BSL Level of Agent Used
Non-Volatile Toxic Chemicals & Radionuclide's
Volatile Toxic Chemicals and Radionuclide’s. I
1-3
Yes
Yes (1,3)
II A2
Yes (4)
II B2 Total Exhaust
Yes (2)
III 4
Radionuclide's as used in nuclear medicine also referred to as radioisotopes.
Cabinets sold in South Africa have a homologations certificate issued by NCRS which will be in accordance with SABS VC8041 cabinets have been certified by an independent SANAS laboratory as complying with all the requirements as set out in the standard or cabinets with an EN Listing are sold locally with a sales permit issued by NCRS
Minute Amount
Small Amount
In no instance should the chemical concentration approach the lower explosion limits of the compound.
Type A2 cabinets used for work with minute quantities of volatile toxic chemicals and tracer amounts of radionuclide’s required as an adjunct to microbiological studies must be exhausted through properly functioning exhaust canopies.
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

9. 4/4/2019
STANDARDS
Major International Standards for Biological Safety Cabinets :
• American Standard NSF/ANSI 49
• SABS VC 8041
• European Standard EN 12469
• Australian Standard AS 2252
• Japanese Standard JIS K 3800
• Chinese Standard SFDA
The most influential locally and throughout Africa vc8041 ,en 12469, NSF 49 South -Africa should soon adopt SANS 1050 witch should make reference to superior parts of En and NSF 49 en some specifications more specific to South - Africa .
Cabinets sold in South Africa have a homologations certificate issued by NCRS which will be in accordance with SABS VC8041 cabinets have been certified by an independent SANAS laboratory as complying with all the requirements as set out in the standard or cabinets with an EN Listing are sold locally with a sales permit issued by NCRS
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

10. STANDARDS COMPARISON FOR CLASS II BIOHAZARD SAFETY CABINETS
4/4/2019
STANDARDS COMPARISON FOR CLASS II BIOHAZARD SAFETY CABINETS
In Flow
Down Flow
Sash
Sound
Light
Last Update
En 12469
0.4 m/s
0.25-
0.5 m/s
Hinged / Sliding
65 Dba
750 Lux
2000
NSF 49
0.51 m/s
Manufacturers specifications
67 Dba
650 Lux
2008
VC 8041
0.45 m/s
0.45-
only hinged
800 Lux
2001
There is also some differences in test methods .
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

11. VALIDATION HEPA Filter Teak Test 4/4/2019
This filter and seals scanned with a photometer to ensure integrity and no leakage.
The filter is challenged with a polydispersed aerosol, the photometer measures the leakage of the filter as a [ersenage.
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

12. VALIDATION Down-flow and inflow velocity. 4/4/2019
Don ward velocity is measured to ensure that the down flows are within the parameters as set out in the standard
A vane or hotwire anemometer can be used .
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

13. VALIDATION Airflow Visualisation 4/4/2019
Smoke patterns to ensure operator protection.
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

14. VALIDATION SECONDARY TESTS Lighting Noise Vibration 4/4/2019
Factory testing but could also be done as per clients request or as per the service engineer findings for field testing.
Vibration
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

15. INSTALLATION RECOMMENDATIONS
4/4/2019
INSTALLATION RECOMMENDATIONS
Avoid Drafts Around BSC Cabinets
Non-Aspirating air inlets should project air away from microbiological safety cabinets (No Coander effect!)
Sidewall HVAC diffusers are unsuitable.
Personnel traffic generates local air movements and possible loss of barrier containment.
The sudden opening and closing of doors can disrupt cabinet airflows.
We will discuss the different exhaust option later on .SABS 0226 :2001 the installation , post installation tests and maintenance of biohazard safety cabinets.
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

16. INSTALLATION RECOMMENDATIONS
4/4/2019
INSTALLATION RECOMMENDATIONS
Avoid Drafts Around BSC Cabinets…
Doors can cause local airflow disruptions and should be considered during cabinet placement.
If cabinet has to be exhausted to atmosphere, consideration should be taken in the placement to allow for exhaust connections.
We will discuss the different exhaust option later on .SABS 0226 :2001 the installation , post installation tests and maintenance of biohazard safety cabinets.
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

17. INSTALLATION RECOMMENDATIONS
4/4/2019
INSTALLATION RECOMMENDATIONS
There should be an allowance of at least 600mm in the direction of exhaust discharge (Filter Replacement)
Power Supply and access to power connections.
In Ventilated rooms where cabinets are place the cabinet should not influence airflow patterns
Exhausting Cabinets placed in unventilated rooms require adequate airflow to the cabinet. (≈0.48m³/s each!).
Location should allow adequate space behind cabinet for testing and cleaning.
Location should allow for system decontamination.
-Power supply for some units more than the standard 15 amp outlet could be needed .
-voltage regulators and ups systems are also used as these could affect airflows.
-Where the power supply is not guaranteed consideration should be given to UPS systems.
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

18. 4/4/2019
EXHAUST SYSTEMS
Solid Connections (Canopy Connections) are used for class I, II B2 and Class 3 Cabinets and are connected to a dedicated leak tight extraction system.
Secondary Extraction fans to be interlocked with Cabinet and cabinet
Exhaust fitted with an automatic anti-backdraft system
There should be volume flow controllers on the system
Gas tight dampers should be provided for decontamination
An alarm system should be fitted to indicate loss of exhaust flow
The exhaust stack should end at least 3m above the roof/parapet wall to avoid re-entrainment by the building
Redundancy should be considered
B2 Cabinet will always be fitted with an exhaust system.
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

19. 4/4/2019
EXHAUST SYSTEMS
Thimble exhaust systems used for class I and II A2 Biohazard safety cabinets.
Because the unit is extracting from the room as well as the cabinet a second filter can be fitted to the exhaust system.
If required by a risk assessment
Decontamination provisions may need to be made.
Examples where air is extracted from a BSL III laboratory we have to install a hepa filter ,
Image Dr PA Jensen
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

20. Equipment: Primary Protection
4/4/2019
Equipment: Primary Protection
Adapted from the Office of Health and Safety –CDC Dr PA Jensen CDC

21. DECONTAMINATION. BSCs must be decontaminated:
4/4/2019
DECONTAMINATION.
BSCs must be decontaminated:
prior to decommissioning and salvage
before physically moving the cabinet and
whenever maintenance work, filter changes or access to contaminated portion of the cabinet.
Para formaldehyde 11g/m³ Cabinet volume -depolymerised via heating Mantle .
Ammonium bicarbonate at >10% is used to neutralize the Paraformaldehyde.
Humidity kept at 70%
Cabinet has to be sealed “leak tight”.
Duct connections should be isolated.
Decontamination minimum 6 hours
Clearly marked “Decontamination In Progress”.
Validation Methods Completed (chemical indicators)
A certificate is issued.
Gas masks should be worn.
Measure levels of formalin in area
Redidue
This the most commonly used.
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

22. DECONTAMINATION: Additional Methods
4/4/2019
DECONTAMINATION: Additional Methods
Vaporized hydrogen peroxide.
System safe
Systems have no residue.
Comparatively Costly
Chlorine Dioxide.
Costly
Corrosive
Chlorine gas is potentially explosive.
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

23. MAINTENANCE AND VALIDATION
4/4/2019
MAINTENANCE AND VALIDATION
DAILY:
Cabinets should be kept clean and dust free in accordance with the manufacturers specifications.
Log filter pressures and note any dramatic changes.
Best agent used for cleaning and swabbing with a suitable disinfectant.
Cabinets should be decontaminated before the validation.
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS

24. MAINTENANCE AND VALIDATION
4/4/2019
MAINTENANCE AND VALIDATION
Bi-Annually - BSC Class II A2
HEPA Filter leak tests.
Down flow Velocity and flow uniformity test.
Inflow velocity test.
If present pre-filters should be replaced.
Smoke test to confirm operator protection.
Visual inspection of cabinet to ensure it is free from cracks and defects.
Inspect extraction system if fitted.
Inspect alarm systems
Vibration
Lighting
Validation certificate should be issued with date and date of next due validation.
Copies of all equipment calibrations must be available.
Best agent used for cleaning and swabbing with a suitable disinfectant.
Cabinets should be decontaminated before the validation.
This course has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through Centers for Disease Control &Prevention (CDC) under the terms of U2G/PS