Biological Safety Cabinets. Biological Safety Cabinets

Transcription

1 Biological Safety Cabinets Biological Safety Cabinets(BSCs) are among the most effective, as well as the most commonly used primary containment devices in laboratories working with infectious agents. Properly maintained Class I and II BSCs, when used in conjunction with good microbiological techniques, provide an effective containment system for safe manipulation of moderate and high-risk microorganisms (Biosafety Level 2 and 3 agents). Both Class I and II BSCs have inward face velocities ( linear feet per minute) that provide comparable levels of containment for laboratory workers and the immediate environment from infectious aerosols generated within the cabinet. 131/405 Biological Safety Cabinets Class II BSCs have the additional advantage of providing protection to the research material by high-efficiency particulate air (HEPA)-filtration of the air flow down across the work surface (vertical laminar flow). Class III cabinets offer the maximum protection to laboratory personnel, the community, and the environment because all hazardous materials are contained in a totally enclosed, ventilated cabinet. 132/405

2 Biological Safety Cabinets BSCs work to protect workers and material from microbes. Avoid working with volatile chemicals in a BSC. 133/405 CLASS I BSC Class I BSCs are no longer being manufactured on a regular basis; many have been replaced by Class II BSCs All of the air from the cabinet is exhausted through a HEPA filter either into the laboratory, or to the outside. The Class I BSC is designed for general microbiological research with low and moderate risk agents, and is useful for containment of mixers, blenders, and other equipment. These cabinets are not appropriate for handling research materials that are vulnerable to airborne contamination, since the inward flow of unfiltered air from the laboratory can carry microbial contaminants into the cabinet. 134/405

3 CLASS I BSC A. front opening, B. work surface, C. window, D. exhaust plenum, E. HEPA filter. 135/ /405 CLASS II BSC The Class II Biological Safety Cabinet is designed with inward air flow at a velocity to protect personnel, HEPA-filtered vertical laminar airflow for product protection, and HEPA-filtered exhaust air for environmental protection. Class II BSCs are classified into two types (A and B) based on construction, air flow velocities and patterns, and exhaust systems. Type A cabinets are suitable for work with microbiological research in the absence of volatile or toxic chemicals and radionuclides, since air is recirculated within the work area. Type B cabinets are further sub-typed into types B1, B2, and B3. Type B cabinets are hard-ducted to the exhaust system, and contain negative pressure plena.

4 CLASS II BSC A. blower, B. rear plenum, C. supply HEPA filter, D. exhaust, E. sash, F. work surface. 137/405 CLASS II BSC 138/405 A. blowers, B. supply HEPA filters, C. sliding sash, D. positive pressure plenums, E. additional supply HEPA filter or back-pressure plate, F. exhaust HEPA filter, G. negative pressure exhaust plenum, H. work surface

5 CLASS III BSC 139/405 The Class III Biological Safety Cabinet is a totally enclosed, ventilated cabinet of gas-tight construction and offers the highest degree of personnel and environmental protection from infectious aerosols, as well as protection of research materials from microbiological contaminants. Class III cabinets are most suitable for work with hazardous agents that require Biosafety Level 3 or 4 containment. All operations in the work area of the cabinet are performed through attached rubber gloves. Supply air is HEPA-filtered, and the cabinet exhaust air is filtered by two HEPA filters in series, or HEPA filtration followed by incineration, before discharge outside of the facility. CLASS III BSC 140/405 A. stand, B. glove ports, C. O-ring for attaching arm-length gloves to cabinet, D. slopped glass viewing window, E. supply HEPA filter, F. exhaust HEPA filter (Note that the second exhaust HEPA filter required for Class III cabinets is not depicted in this diagram), G. double-ended autoclave.

6 Biological Safety Cabinets Protects operator Protects the environment Protects the product Reduces the risk of airborne infection by reducing the escape of aerosols Laminar Flow Clean Benches Protects the product Blows aerosols into the operator s face. Does not protect the operator Should not be used with potential pathogens Is not a Biological Safety Cabinet 141/405 EFFECTIVE USE OF BIOLOGICAL SAFETY CABINETS Turn on the lights Turn on the fan Allow the fan to operate a minimum of five minutes before manipulations are begun in the cabinet. Some cabinets are equipped with ultraviolet light. These must be turned off during the day while laboratory personnel are occupying the room. Hands and arms should be washed well with germicidal soap before and after work in the cabinet. Interior surfaces of the work area should be disinfected by wiping them thoroughly with 70% alcohol. 142/405

7 143/ /405 EFFECTIVE USE OF BIOLOGICAL SAFETY CABINETS Everything needed for the complete procedure should be placed in the cabinet before starting so that nothing passes in or out through the air barrier until the procedure is completed. Do not place anything over the front intake or rear exhaust grill in units having a solid work surface. As a general rule, keep equipment at least four inches inside the cabinet window and perform transfer of viable materials as deeply into the cabinet as possible. After all materials have been placed in the cabinet, wait 2-3 minutes before beginning work. This will allow sufficient time for the cabinet air to purge airborne contamination from the work area. EFFECTIVE USE OF BIOLOGICAL SAFETY CABINETS Opening and closing laboratory doors can cause disruptive drafts that allow microorganisms to penetrate the air barrier. The movement of objects including hands and arms causes turbulent air currents which disrupt the air barrier and allow escape and entrance of airborne contaminants. If a centrifuge must be used in the cabinet, do not perform other research activities in the cabinet while the centrifuge is operating. Do not use a Bunsen Burner in a biological safety cabinet. The flame causes turbulence in the air stream and the heat generated may damage the HEPA filter. If a procedure requires the use of a flame, a burner with a pilot light should be used.

8 Myths and Lies "I can use a biological safety cabinet just as if it were a fume hood..." "If I work in a biohazard cabinet, I don't have to be as careful with my technique..." "I use the cabinet's UV light, so I don't need to decontaminate the work area..." "A total exhaust biohazard cabinet will give better protection than a Type A cabinet..." "There's nothing wrong with using the biohazard cabinet to store material when not in use." "All biohazard cabinets should operate continuously, 24 hours-a-day." "If I leave my Type A cabinet running continuously, it will clean all the air in the room to Class 100 conditions." 145/405 BIOHAZARD WASTE Cultures and stocks of infectious agents and associated biologicals Human blood and blood products Pathological wastes Contaminated sharps Contaminated animal carcasses, body parts, and bedding Laboratory wastes Any other material and contaminated equipment which presents a significant danger of infection 146/405

9 Infectious Waste Disposal All infectious waste destined for disposal shall be placed in closable, leak-proof containers or bags that are colorcoded or labeled. 147/405 Infectious Waste Disposal Immediately after use, sharps, i.e., broken glass, needles, pipettes, etc., shall be placed in closable, labeled or color-coded leak-proof, puncture resistant, disposable containers. These containers shall be easily accessible to personnel and located in the area of use. BIOHAZARD 148/405

10 New Mexico State University Environmental Health & Safety Date BIOHAZARD WASTE ALWAYS place sharps in puncture resistant containers for disposal. 149/405 Signs and Labeling BSL-1 Laboratory BIOHAZARD All Personal Protective Equipment shall be removed prior to leaving this work area. Eating, drinking, smoking applying cosmetics or lip balm and handling contacts lenses area prohibited in this work area. Name of infectious agent(s): Transmission route(s): Special requirements for entering this area: Emergency contacts Name: Title: Phone: EH&S office (M-F 8-5) (after hours) 911. *Bi osa fety Level 2 is similar t o B S L -1 and is suita b le fo r w ork involving agents of moderate potential hazard to personnel and the environm ent. It differs from BSL-1 in that 1.Lab personnel have specific training in handling pathogenic agents and directed to competent scientist; 2. Access to the lab is limited when work is being conducted: 3. E xtrem e p re cauti ons are tak en w ith c ontaminated sharp item s and 4. Certain procedures in which infectious aerosols or splashes may be created are conducted in biological safety cabinets or other physical containment equipment 150/405

11 Treated Biohazard Wastes Incineration in an approved incinerator. Steam sterilization at sufficient time and temperature to destroy infectious agents in waste ("autoclaved"). Chemical disinfection where contact time, concentration, and quantity of the chemical disinfectant are sufficient to destroy infectious agents in the waste. 151/405 실험실안전밀폐기준 현행유전자재조합지침 ( 복지부고시 제 호, 1997 년 4 월 ) 에따름 See p. 95 in Appendix B 152/405

12 Summary It is up to you to protect yourself, your co-workers, the community, and the environment! Good lab practices are fundamental Communicate about hazardous materials PLAN! PLAN! PLAN! When in doubt, ASK!!!! Practicing Safe Science Glassware Washing Hazards 153/405