Biosafety & Engineering Controls PDF

BIOSAETY & Engineering Controls Dr. Nazir Ahmed Lone (PhD, Postdoc, Fulbright Alumni) Associate Professor (Immunology &Virology) Department of Biological Sciences [email protected] Lecture-5-6...

BIOSAETY & Engineering Controls Dr. Nazir Ahmed Lone (PhD, Postdoc, Fulbright Alumni) Associate Professor (Immunology &Virology) Department of Biological Sciences [email protected] Lecture-5-6 1  Objectives At the conclusion of this module, Students will be able to: 1. Discuss the Emerging Infectious Diseases and their Risk 2. Describe and discuss Engineering Controls in Bio-Labs. 3. Discuss and describe the testing and certification of a biological safety cabinet (BSC). 4. Discuss the principles and operation of high efficiency particulate air (HEPA) filters. 5. Describe and discuss the types of BSCs. 6. Describe and discuss the proper operations within a BSC. 2  Definition – Engineering Controls Eliminate or reduce exposure to a biological, chemical or physical hazard through the use or substitution of engineered machinery or equipment – placing a barrier between the worker and the hazard Hierarchy of controls:  Elimination  Substitution  Engineering controls  Administrative controls  Personal protective equipment 4  Engineering Controls Primary Barriers  Biological safety cabinets Secondary Barriers  Building design 5  Engineering Controls Examples include self-capping syringe needles, ventilation systems such as a biological safety cabinet, fume hood and sound-dampening materials to reduce noise levels: HVAC Duct Liner Biological Safety Cabinet Chemical Fume Needles and Syringes Hood 6  Engineering Controls Additional examples include radiation shielding, centrifuge cups, pipeting devices and safety interlocks: X-Ray Glass Safety Centrifuge Cups Mechanical Pipet Aid Safety Interlock Switch 7  Types of Ventilation Equipment Particulate Protection Personnel Product Environmental Fume Hoods X Clean Benches X Class I BSC X X Class II BSC X X X Class III BSC X X X John Bivona University of Chicago 8  Fume Hoods Personnel protection only Exhausts air to the outside Does not offer product or environmental protection Draws contaminants in the laboratory air directly over the product being worked on Used for work with chemical hazards John Bivona University of Chicago 9  Clean Benches Product protection only Provided by creating airflow generated through a HEPA filter Discharge air goes directly into workroom Used when the product is not hazardous but must be kept contaminant free Preparation of non-hazardous mixtures and media John Bivona University of Chicago 10  Biological Safety Cabinets (BSC) Designed to contain biological hazards Inward airflow for personnel protection HEPA filtered exhaust air for environmental protection Supply air HEPA filter for product protection (except Class I) John Bivona University of Chicago 11  Biological Safety Cabinets  Primary means of containment  Designed to provide protection for - Personnel - Product - Environment  Three design types - Class I, Class II, and Class III 12  Testing and Certification  National Sanitation Foundation (NSF) International Standard/American National Standard (January 24, 2007)  Standard No. 49 - 2007 - Performance Criteria - Minimum Requirements for Design, Manufacture, and Testing - NSF 49 Seal  Testing is done by the manufacturer prior to shipping of cabinet 13  Testing and Certification  Field test (certification) is required - Prior to service - After repairs or relocation - Annually  Certification reports kept in the equipment books 14  Testing and Certification Field test (certification) performance criteria: - Down-flow air velocity and volume - In-flow air velocity - Air flow smoke pattern - HEPA filter leak test - Cabinet leak test 15  HEPA Filters  High efficiency particulate air (HEPA) filter  Efficiently remove microscopic contaminants from air  Remove particles < 0.3 µm with an efficiency of 99.97%  DO NOT capture volatile chemicals or gases 16  HEPA Filters  Single sheet of borosilicate fibers  Treated with a wet-strength, water-repellant binder  Pleated to increase surface area  Corrugated aluminum separators divide the pleats 17  HEPA Filters Capture particles through:  Impaction  Interception  Diffusion John Bivona University of Chicago 18 0.3  HEPA Filter  Filter can be easily damaged by careless handling  Filter integrity must be certified annually, and after installation or relocation 19 BSC Classification Dr. Nazir Ahmed Lone (PhD, Postdoc, Fulbright Alumni) Associate Professor (Immunology &Virology) Department of Biological Sciences [email protected] Lecture-7 20  BSC Classification  Class I  Class II - Type A1 (A); A2 (A/B3, B3), B1, B2, B3  Class III NSF Classification of 2007 Class II (laminar flow) biosafety cabinetry; NSF/ANSI 49-2007 CDC/NIH, Primary Containment for Biohazards: Selection, Installation and Use of Biological Safety Cabinets, Appendix A, Biosafety in Microbiological and Biomedical Laboratories, 5th edition, 2007. 21  Class I BSC Provides: – Personnel Protection (in-ward air flow) – Environmental Protection (HEPA) Product Protection LABCONCO 22  Class II Type A BSC Provides: - Personnel Protection (in-ward air flow)  Type A1 - 75 fpm  Type A2 - 100 fpm - Environmental Protection (HEPA) - Product Protection (downward flow of HEPA- filtered air) John Bivona University of Chicago 23  Class II Type A BSC A. Front opening - 75 fpm Type A1 - 100 fpm Type A2 B. Sash C. Exhaust HEPA filter D. Supply HEPA filter E. Positive pressure plenum F. Negative pressure plenum 24  Class II Type A BSC  HEPA-filtered air is re-circulated to the room, or to the environment through an exhaust canopy  Type A1 cabinets are not suitable for work with volatile or toxic chemicals, or volatile radionuclides · Type A2 cabinets can be used with minute quantities of volatile toxic chemicals and tracer amounts of radionuclides but the exhaust must be through an exhaust canopy. · HEPA filters can manage airflow up to 250 feet per minute (FPM) with minimal pressure drop. 25  Class II Type A BSC  Internal blower  70% re-circulated in the BSC  Inflow velocity  30% exhausted from a - 75 fpm (Type A1) common plenum to: - 100 fpm (Type A2) - the room (Type A1)  Downward laminar flow - facility exhaust system splits 2-6 inches above (Type A2) work surface between  Plenum: front and rear grills + Pressure (Type A1) - Pressure (Type A2) 26  Class II Type B BSC Type B1 Type B2  Minimal average inflow  Minimal average inflow velocity velocity 100 fpm (0.5 m/sec) 100 fpm (0.5 m/sec)  40% air re-circulated  0% air re-circulated  60 % air exhausted  100 % air exhausted  All biologically contaminated  All biologically contaminated ducts and plenums under ducts and plenums under negative pressure or surrounded by negative negative pressure or pressure ducts and plenums surrounded by negative pressure ducts and plenums “Total Exhaust” 27  Class II Type B2 BSC Type B2 cabinets may be used for work with volatile toxic chemicals and radionuclides required as an adjunct to microbiological studies John Bivona University of Chicago 28  Class III BSC Gas-tight containment enclosure Product, personnel, and environmental protection Minimum air intake velocity through a glove port of 100 fpm Air must be exhausted to the outdoors Exhaust air is treated by double HEPA filtration or HEPA filtration and incineration John Bivona University of Chicago 29  Class III BSC Operation in cabinet performed through rubber gloves Operates under negative pressure (0.5 inches w.g.) (120 Pascals) Supply air is HEPA filtered Must be connected to a double door autoclave and/or chemical dunk tanks to sterilize or disinfect all exiting materials John Bivona University of Chicago 30  Ultraviolet (UV) Lights The CDC, NIH and ABSA all agree that UV lamps are not recommended nor required in BSCs UV light in your BSC is only useful as an extra precaution in keeping the work area decontaminated between uses UV light has very little power to penetrate even through a dust particle Frequent cleaning required Energy output must be measured 31  BSC Connections Hard Connection Sealed joint between duct and cabinet Exhaust system flow = cabinet flow Used with B1 and B2 BSCs Canopy Connection Air gap between duct and cabinet Exhaust flow is > than cabinet flow Previously called a thimble connection Used with A1 and A2 BSCs John Bivona University of Chicago 32 BSC Classification 33  Operation in a BSC  Class II BSC are designed to capture horizontally nebulized spores in the downward flowing air  Workflow from clean to contaminated (“dirty”) 34  Operation in a BSC  Plan your work  Decontaminate BSC prior to use  Place absorbent pad on work surface  Set up work area with all necessary items - Centrifuge - Pipettes - Waste containers - Disinfectant Biosafety in Microbiological and Biomedical Laboratories [HHS Publication No.(CDC) - 5th ed., Feb 2007] Laboratory Biosafety Manual 35 [World Health Organization – 3rd ed., 2004]  Operation in a BSC  After setup, allow 4-5 minutes for air flow to resume  Place hands in BSC and wait 1 minute before beginning work  Refrain from removing hands from BSC during operation  Immediately clean-up small spills Biosafety in Microbiological and Biomedical Laboratories [HHS Publication No.(CDC) - 5th ed., Feb 2007] Laboratory Biosafety Manual 36 [World Health Organization – 3rd ed., 2004]  Operation in a BSC  Surface decontaminate items before removal from the BSC  Decontaminate cabinet following use: - Work surface - Sides - Back - Sash interior glass 37  Operation in a BSC Explosion in a Cabinet 38 Operation in a BSC 39  Operation in a BSC Improper Procedures Particles from Hands 40  Principle of Class III Biological Safety Cabinet (BSC) Researcher Material is enclosed in an air-tight cabinet and manipulated by Agent the researcher from outside using non- permeable, flexible gloves 41  Class III Biological Safety Cabinet System 42  When should a cabinet be decontaminated? Decontaminate with a suitable disinfectant: - All interior work surfaces - All exposed interior surfaces Gas decontamination recommended: - If cabinet was used with BSL-2 or BSL-3 agents - Depolymerized paraformaldehyde - Vaporized Hydrogen Peroxide (VHP) Class II (laminar flow) biosafety cabinetry, National Sanitation Foundation (NSF) International Standard/American National Standard [NSF/ANSI 49-2007], Annex G (January 24, 2007) 43  When should a cabinet be decontaminated? When access to any contaminated portion of the cabinet is required for: - Maintenance work - Filter changes - Performance tests After spills and splashes Before relocation to another area Class II (laminar flow) biosafety cabinetry, National Sanitation Foundation (NSF) International Standard/American National Standard [NSF/ANSI 49-2007], Annex G (January 24, 2007) 44  Summary - I Engineering Controls eliminate or reduce exposure to a hazard by use or substitution of engineered machinery or equipment. A BSC is a primary means of containment providing protection of personnel, the product, and the environment. The BSC types are Types I, II, and III. Certification of a BSC is done according to standards, and must be done prior to use, after repairs or relocation, and annually. 45  Summary - II A HEPA filter removes microscopic contaminants from air (particles < 0.3 µm with an efficiency of 99.97%), but DOES NOT capture volatile chemicals or gases. Operations within a BSC must be planned, and strict work practices must be followed. 46 ANY QUESTIONS T he E nd ! 47