BIOLOGICAL SAFETY CABINET MIT-EHS Biosafety Program - 2014
Learning objectives Learn about different types of laboratory ventilation equipment and their uses in biological research Learn about best practices when working in a Biological Safety Cabinet (BSC). Tips for Level II inspection
Brief history of Biosafety Cabinets First became commercially available in 1950 thanks to the development of HEPA filter in the 1940s.
What is a Biological Safety Cabinet? Primary containment for working safely with infectious materials Containment during procedures (pipetting, centrifugation) that generate biological aerosols
What is an aerosol? Stable suspension of particles in a gas. Particles- solid or liquid (droplets) Gas- in this case mostly air particles Aerosol Droplet Size < 5 μm > 5 μm Visibility Invisible Often visible Travel distance > 3 ft < 3ft Behavior Similar to a gas, will not settle, removed by the HVAC system Gravity will cause droplets to settle on surfaces
Why do we use a BSC? Personnel Material/product Environment
Types of lab ventilation equipment Ventilation Equipment Chemical Fume Hoods Biological Safety Cabinets Clean Benches Class I Class II Class III Class II Class II Class II Class II Type A1 Type A2 Type B1 Type B2
Parts of a BSC Blower motor Filter exhaust housing Plenum Sash Work space Back grill Sash Drain valve Front grill
Equipment Chemical * Fume hood Overview of ventilation equipment uses (not common at MIT) Ventilation (exhaust) Non-volatile toxic chemical and radionucleotides Applications 100% non-filtered air Yes Yes Clean Bench 100% HEPA filtered air No No Volatile toxic chemicals and radionucleotides Class I BSC 100% HEPA filtered air Yes Yes, when exhausted outdoors Class II Type B1 60% HEPA filtered air 40% recirculated HEPA filtered air Yes Yes but in minute amounts Class II Type B2 100% HEPA filtered air Yes Yes, small amounts Class III 100% HEPA filtered air Yes Yes, small amounts * Equipment designed for work with biological material not requiring sterile conditions. Equipment designed for work mainly with biological/infectious materials Equipment designed for work not involving biological materials
Protection from Biological hazards Equipment Personnel Material Environment Chem. Fume Hood
BSC vs. Chemical Fume hood BSCs HEPA filtered air Protection Personnel Product Environment Recirculates filtered air into room Suitable for sterile work Chemical Fume hood Non filtered air Protection Personnel Exhaust air outside the building Uses Chemicals Radionucleotides Non-sterile work
Protection from Biological hazards Equipment Personnel Material Environment Chem. Fume Hood Clean Bench
Clean bench not a BSC Must NOT be use with Biohazardous materials including cell culture Chemicals Radionucleotides Horizontal Laminar Flow clean bench Vertical Laminar Flow clean bench
Protection from Biological hazards Equipment Personnel Material Environment Chem. Fume Hood Clean Bench Class I BSC
Class I BSC
Protection from Biological hazards Equipment Personnel Material Environment Chem. Fume Hood Clean Bench Class I BSC Class III BSC
Class III BSC
Protection from Biological hazards Equipment Personnel Material Environment Class II A1 Class II A2 Class II B1 & B2
Class II, Type A1 Recirculates 70% of HEPA filtered air to work surface Exhausts 30% of HEPA filtered air to room. Use Biohazardous materials Cell culture Do NOT use Volatile toxic chemicals Radionucleotides
Class II, Type A2 Recirculates 70% of HEPA filtered air to work surface Exhausts 30% of HEPA filtered air to room. Use Biohazardous materials Cell culture Do NOT use Volatile toxic chemicals Radionucleotides
Canopy (thimble) unit for ducting Class II, Type A BSC Proper way to connect Class II, Types A1 & A2 BSCs to building exhaust system Canopy prevents disturbance of internal cabinet airflow 1 gap between canopy and exhaust filter housing Canopy must removable or design to allow operational testing Audible and visual alarm 1 gap (A) balancing damper (B) flexible connector to exhaust system (C) cabinet exhaust HEPA filter housing (D) canopy unit (E) BSC
Canopies
What is an HEPA filter? HEPA (High Efficiency Particulate Air or Arrestance) Filter Porous media, usually fiberglass. Fibers randomly oriented in the mat. Most of the mat is air (>90%)
HEPA filter system construction
How does a HEPA filter work? HEPA (High Efficiency Particulate Air) filter in the exhaust and supply areas of BSC.
HEPA filter removal efficiency Minimum filter efficiency = 99.97% at particles of 0.3 μm (300 nm) Filter efficiency removal of larger and smaller particles is greater than 99.97%
HEPA filter removal efficiency- only
BSC vapor handling Credits: The Baker Company. Class II Biological Safety Cabinet Vapor Handling Posted by Becky Metivier on Thu, Jan 31, 2013 @ 09:42 AM
Protection from Biological hazards by type of equipment Equipment Personnel Material Environment Chem. Fume Hood Clean Bench Class I BSC Class II B1, B2 BSC Class III BSC
Class II, Type B1 & B2 BSC Type B1 Type B2 40% air re-circulated in BSC 60 % air exhausted Use Biohazardous materials Volatile toxic chemicals Radionucleotides May work with tracer amounts of these materials in the back part of surface in cabinet (exhausted) Must be hard-ducted 0% air re-circulated in BSC 100 % air exhausted Use Biohazardous materials Handling cytotoxic or hazardous drugs Volatile toxic chemicals (moderate amounts) Radionucleotides Must be hard-ducted
Class II, Type B1 BSC Class II Type B1 (Classic design)
Class II, Type B2 BSC Class II Type B2
How to work in a BSC BEFORE starting your procedure DURING work in the BSC AFTER finishing your procedure
How to work in a BSC BEFORE starting your procedure
Before BSC use Ensure window sash is at proper operating height (approx. 8 or 10 in. according to manufacturers instructions) Turn on blower and light at least 4 min. prior to use to purge still air in BSC Spray appropriate disinfectant on paper towel and wipe from back to front (clean to dirty), use tool for back wall Monitor alarms, pressure gauge or flow indicators for any major fluctuations or use tissue technique Make sure vacuum trap is in place. Wipe all materials with appropriate disinfectant before placing inside BSC
Ergonomic considerations when working in a BSC Chair Table and work surface Location of controls Environmental factors
How to work in a BSC DURING work in the BSC
Grills and work surface Keep front, side and rear grilles clear of clutter Load only the material required for the procedure in the center of the cabinet interior (at least 4-6 inch from front grill) Avoid frequent motions in and out of the cabinet
Hand/arm motions
Arrangement of materials Arrange work surface from clean to dirty
Vacuum line protection
Flames No open flames in BSC. (CAB/ESCRO policy) Electrical system may not be spark-proof
Spills clean up If a spill occurs in the cabinet: Keep BSC running to contain aerosols Follow biological spill cleanup protocol If spill overflows into catch basin under cabinet surface: Ensure drain valve is closed Pour disinfectant onto surface and through grilles Allow at least 20 min contact time Soak up with paper towels Connect flexible tubing to drain valve Drain basin into disinfectant filled container Dispose of exposed materials in biohazardous waste
How to work in a BSC AFTER finishing your procedure
Unloading and disinfecting BSC Leave BSC blower running Wipe down materials with appropriate disinfectant and take everything out of cabinet Wipe down cabinet surfaces with appropriate disinfectant from clean to dirty areas UV lights are not a dependable disinfection method and not recommended due to lack of performance verification by current NSF (2011) standard.
Maintenance/certification BSCs must be tested and certified annually or if: A new cabinet is being installed A cabinet has been moved A cabinet is in need of troubleshooting or repairs ALL maintenance and certification conducted by an approved/certified vendor Never attempt repairs yourself Drain pan recommended to be clean periodically
Contact Biosafety if you Plan to purchase a new BSC Plan to move a BSC Need help selecting a location for your BSC Need personnel trained in the use of BSC
VIDEO DEMONSTRATION MIT-EHS Biosafety Program
Video demo bad laboratorian