![]() ![]() Practices such as the following are recommended for optimum protection: Limited amounts of volatile chemicals in Types B1 and B2 ONLYīiological safety cabinets must be used with good practices in order to provide protection to the worker. Manipulations of infectious or potentially infectious materials that may cause aerosols.Work involving microorganisms assigned to biosafety levels 1, 2, and 3.Types of work that can be done in a biological safety cabinet: The tabletop model of a Class II, Type A2 BSC (A) front opening (B) sash (C) exhaust HEPA filter (D) supply HEPA filter (E) positive pressure common plenum (F) negative pressure plenum. Only Type A2-exhausted or Types B1and B2 BSCs exhausting to the outside should be used when working with volatile, toxic chemicals, and amounts must be limited. HEPA filters are effective at trapping particulates and thus infectious agents but do not capture volatile chemicals or gases. ![]() Exhaust air from Types B1 and B2 BSCs must be discharged directly to the outdoors via a hard connection. Depending on the type of Class II cabinet, exhaust air may be re-circulated to the laboratory (Types A1 and A2) or discharged from the building via a canopy or “thimble” connected to the building exhaust. Exhaust air is passed through a certified HEPA filter and is particulate-free, which provides environmental protection. The downward flow of HEPA-filtered air provides product protection by minimizing the chance of cross-contamination across the work surface of the cabinet. Airflow is drawn into the front grille of the cabinet, providing personnel protection. All Class II BSC types provide personnel, environmental and product protection. The Class II biological safety cabinet (BSC) comes in a variety of types. Hazardous chemicals, potential biohazards, radionuclides and any material that is a potential allergen cannot be used in this type of equipment.Ī clean bench must never be substituted for a biological safety cabinet. Work with non-hazardous materials where clean, particle-free air quality is required.Types of work that can be done in a laminar flow “clean bench”: The vertical laminar flow “clean bench” (A) front opening (B) sash (C) supply HEPA filter (D) blower. Horizontal airflow “clean benches” must never be used as a substitute for a biological safety cabinet. The worker will be exposed to the materials being manipulated on the clean bench potentially resulting in hypersensitivity, toxicity or infection depending on the materials being handled. Clean benches should never be used when handling cell culture materials, drug formulations, potentially infectious materials, or any other potentially hazardous materials. They can be used for certain clean activities, such as the dust-free assembly of sterile equipment or electronic devices. These devices only provide product protection. The laminar flow “clean bench” discharges HEPA-filtered air from the back or top of the cabinet across the work surface and toward the user. The direction of the airflow out of the cabinet is very different, however, and therefore each piece of equipment is appropriate for specific types of work. Both of these pieces have high efficiency particulate air (HEPA) filters, which control airborne particulate materials by removing the most penetrating particle size of 0.3 μm with an efficiency of at least 99.97%. The common thread is that the equipment provides laminar air flow for a “clean” work area, but it is important to know that not all equipment provides additional personnel or environmental protection.īelow is a general guidance on the differences between two common pieces of lab equipment at UNH that both provide laminar flow of air biological safety cabinets (BSC) and the laminar flow “clean bench”. An important thing to note, however, is that not all of these “hoods” are created equally in fact, they have very different protective capabilities. When you walk into a research laboratory, there is a piece of equipment that is often referred to by many different names: cell culture hood, tissue culture hood, laminar flow hood, PCR hood, clean bench, or biosafety cabinet. ![]()
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