Biosafety cabinet: Difference between revisions
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|name = Biological safety cabinet |
|name = Biological safety cabinet |
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|image = Influenza virus research.jpg |
|image = Influenza virus research.jpg |
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|caption = A microbiologist |
|caption = A microbiologist a biological safety cabinet |
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|acronym = BSC |
|acronym = BSC |
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|other_names = Biosafety cabinet |
|other_names = Biosafety cabinet |
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|related = [[Laminar flow cabinet]], [[Fume hood]] |
|related = [[Laminar flow cabinet]], [[Fume hood]] |
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A '''biological safety cabinet''' |
A '''biological safety cabinet''' '''biosafety cabinet ''' is an enclosed, ventilated workspace for safely working with [[]] agents in the [[laboratory]]. Several different types exist, differentiated by the specifics of construction. |
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== Purposes == |
== Purposes == |
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The primary purpose of a BSC is to protect the laboratory worker and the surrounding environment from pathogens. All exhaust air is [[HEPA]]-filtered as it exits the biosafety cabinet.<ref name="IAState2005">{{cite web|url=http://www.ehs.iastate.edu/cms/default.asp?action=article&ID=40|title=Biosafety Cabinets|author=Iowa State University|year=2005|accessdate=April 24, 2010}}</ref> This is in contrast to a [[laminar flow cabinet|laminar flow]] clean bench, which blows unfiltered exhaust air towards the user and is not safe for work with pathogenic agents.<ref name="CDC2000">{{cite book|last1=U.S. Centers for Disease Control and Prevention|last2=U.S. National Institutes of Health|title=Primary Containment for Biohazards: Selection, Installation and Use of Biological Safety Cabinets|publisher=U.S. Centers for Disease Control and Prevention|year=2000|url=http://www.cdc.gov/od/ohs/pdffiles/BSC-3.pdf}}</ref>{{rp|13}}<ref name="UPenn2009">{{cite web|url=http://www.ehrs.upenn.edu/programs/bio/biologicalsafetycabinets/cleanbenches.html|title=Clean Benches vs. Biosafety Cabinets|author=University of Pennsylvania|date=November 6, 2009|accessdate=April 24, 2010}}</ref> Neither are most BSCs safe for use as fume hoods.<ref name="IAState2005"/> However, most classes of BSCs have a secondary purpose to maintain the sterility of materials inside (the "product"). |
The primary purpose of a BSC is to protect the laboratory worker and the surrounding environment from pathogens. All exhaust air is [[HEPA]]-filtered as it exits the biosafety cabinet.<ref name="IAState2005">{{cite web|url=http://www.ehs.iastate.edu/cms/default.asp?action=article&ID=40|title=Biosafety Cabinets|author=Iowa State University|year=2005|accessdate=April 24, 2010}}</ref> This is in contrast to a [[laminar flow cabinet|laminar flow]] clean bench, which blows unfiltered exhaust air towards the user and is not safe for work with pathogenic agents.<ref name="CDC2000">{{cite book|last1=U.S. Centers for Disease Control and Prevention|last2=U.S. National Institutes of Health|title=Primary Containment for Biohazards: Selection, Installation and Use of Biological Safety Cabinets|publisher=U.S. Centers for Disease Control and Prevention|year=2000|url=http://www.cdc.gov/od/ohs/pdffiles/BSC-3.pdf}}</ref>{{rp|13}}<ref name="UPenn2009">{{cite web|url=http://www.ehrs.upenn.edu/programs/bio/biologicalsafetycabinets/cleanbenches.html|title=Clean Benches vs. Biosafety Cabinets|author=University of Pennsylvania|date=November 6, 2009|accessdate=April 24, 2010}}</ref> Neither are most BSCs safe for use as fume hoods.<ref name="IAState2005"/> However, most classes of BSCs have a secondary purpose to maintain the sterility of materials inside (the "product"). |
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== Classes == |
== Classes == |
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Class I cabinets provide personnel and environmental protection but no product protection. Inward airflow is maintained at a minimum velocity of 75 ft/min. These BSCs are commonly used to enclose specific equipment (''e.g.'' centrifuges) or procedures (''e.g.'' aerating cultures) that potentially generate aerosols. BSCs of this class are either ducted (connected to the building exhaust system) or unducted (recirculating filtered exhaust back into the laboratory).<ref name="CDC2000"/>{{rp|6}} |
Class I cabinets provide personnel and environmental protection but no product protection. Inward airflow is maintained at a minimum velocity of 75 ft/min. These BSCs are commonly used to enclose specific equipment (''e.g.'' centrifuges) or procedures (''e.g.'' aerating cultures) that potentially generate aerosols. BSCs of this class are either ducted (connected to the building exhaust system) or unducted (recirculating filtered exhaust back into the laboratory).<ref name="CDC2000"/>{{rp|6}} |
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===Class II=== |
===Class II=== |
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[[Image:Laminar flow hood 2.jpg|thumb|right|A class II safety cabinet used for handling ''[[Leishmania]]''.]] |
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Class II cabinets provide both kinds of protection since makeup air is also HEPA-filtered. There are four types: Type A, Type B1, Type B2, and Type B3. |
Class II cabinets provide both kinds of protection since makeup air is also HEPA-filtered. There are four types: Type A, Type B1, Type B2, and Type B3. |
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The principle of operation involves using a fan mounted in the top of the cabinet to draw a curtain of sterile air over the products that are being handled. The air is then drawn underneath the work surface and back up to the top of the cabinet where it passes through the HEPA filters. The air that is exhausted is made up by air being drawn into the front of the cabinet underneath the work surface. The air being drawn in acts as a barrier to potentially contaminated air coming back out to the operator. |
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The Class II Type A cabinet has a minimum inflow velocity of 75 ft/min. The filtered makeup air is divided equally over the work surface at about two to six inches above the work surface. Exhaust is drawn at the bottom of the cabinet where it rises to the top. At the top of the cabinet, 70% of the air recirculates through the supply HEPA filter, the other 30% of air exhausted through the exhaust HEPA filter. This is due to the relative sizes of the two filters, and dampers typically allow the adjustment of this ratio. This type is not safe for work with hazardous chemicals except when ducted, usually with a "thimble" or canopy hood to avoid disturbing internal air flow.<ref name="CDC2000"/>{{rp|8–9}} |
The Class II Type A cabinet has a minimum inflow velocity of 75 ft/min. The filtered makeup air is divided equally over the work surface at about two to six inches above the work surface. Exhaust is drawn at the bottom of the cabinet where it rises to the top. At the top of the cabinet, 70% of the air recirculates through the supply HEPA filter, the other 30% of air exhausted through the exhaust HEPA filter. This is due to the relative sizes of the two filters, and dampers typically allow the adjustment of this ratio. This type is not safe for work with hazardous chemicals except when ducted, usually with a "thimble" or canopy hood to avoid disturbing internal air flow.<ref name="CDC2000"/>{{rp|8–9}} |
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==See also== |
==See also== |
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{{Commons|Fume hood}} |
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* [[Biocontainment]] |
* [[Biocontainment]] |
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* [[Fume hood]] |
* [[Fume hood]] |
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{{reflist}} |
{{reflist}} |
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{{Laboratory equipment}} |
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[[Category:Biological hazards]] |
[[Category:Biological hazards]] |
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[[Category:Safety equipment]] |
[[Category:Safety equipment]] |
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Revision as of 18:01, 25 April 2010
 A microbiologist performing influenza research within a biological safety cabinet | |
| Acronym | BSC |
|---|---|
| Other names | Biosafety cabinet |
| Uses | Biocontainment |
| Related items | Laminar flow cabinet, Fume hood |
A biological safety cabinet (BSC), biosafety cabinet, or microbiological safety cabinet is an enclosed, ventilated workspace for safely working with pathogenic agents (or material potentially contaminated with pathogens) in the laboratory. Several different types exist, differentiated by the specifics of construction.
Purposes
The primary purpose of a BSC is to protect the laboratory worker and the surrounding environment from pathogens. All exhaust air is HEPA-filtered as it exits the biosafety cabinet, removing harmful bacteria and viruses.[1] This is in contrast to a laminar flow clean bench, which blows unfiltered exhaust air towards the user and is not safe for work with pathogenic agents.[2]: 13 [3] Neither are most BSCs safe for use as fume hoods.[1] However, most classes of BSCs have a secondary purpose to maintain the sterility of materials inside (the "product").
Classes
The U.S. Centers for Disease Control and Prevention classifies BSCs into three classes.[2]: 6 These classes and the types of BSCs within them are distinguished in two ways: the level of personnel and environmental protection provided and the level of product protection provided.
Class I
Class I cabinets provide personnel and environmental protection but no product protection. Inward airflow is maintained at a minimum velocity of 75 ft/min. These BSCs are commonly used to enclose specific equipment (e.g. centrifuges) or procedures (e.g. aerating cultures) that potentially generate aerosols. BSCs of this class are either ducted (connected to the building exhaust system) or unducted (recirculating filtered exhaust back into the laboratory).[2]: 6
Class II
Class II cabinets provide both kinds of protection since makeup air is also HEPA-filtered. There are four types: Type A, Type B1, Type B2, and Type B3.
The principle of operation involves using a fan mounted in the top of the cabinet to draw a curtain of sterile air over the products that are being handled. The air is then drawn underneath the work surface and back up to the top of the cabinet where it passes through the HEPA filters. The air that is exhausted is made up by air being drawn into the front of the cabinet underneath the work surface. The air being drawn in acts as a barrier to potentially contaminated air coming back out to the operator.
The Class II Type A cabinet has a minimum inflow velocity of 75 ft/min. The filtered makeup air is divided equally over the work surface at about two to six inches above the work surface. Exhaust is drawn at the bottom of the cabinet where it rises to the top. At the top of the cabinet, 70% of the air recirculates through the supply HEPA filter, the other 30% of air exhausted through the exhaust HEPA filter. This is due to the relative sizes of the two filters, and dampers typically allow the adjustment of this ratio. This type is not safe for work with hazardous chemicals except when ducted, usually with a "thimble" or canopy hood to avoid disturbing internal air flow.[2]: 8–9
The Class II Type B1, B2, and B3 cabinets have a minimum inflow velocity of 100 ft/min. Type B1 cabinets must be hard-ducted to an exhaust system. As with the type A cabinet, 70% of air from the rear grille is recirculated. Since exhaust air is drawn from the rear grille, work with chemicals should be conducted in the rear of the cabinet.[2]: 10 In the Type B2 cabinet, no air is recirculated within, making this type of BSC expensive to operate.[2] In the Type B3 cabinet, all air is exhausted outside the building. In all other respects the Type B3 cabinet is constructed similarly to a Class II Type A cabinet.[2]: 9–11
Class III
The Class III cabinet, generally only installed in maximum containment laboratories, is specifically designed for work with BSL-4 pathogenic agents, providing maximum protection. The enclosure is gas-tight, and all materials enter and leave through a dunk tank or double-door autoclave. Gloves attached to the front prevent direct contact with hazardous materials. These custom-built cabinets often attach into a line, and the lab equipment installed inside is usually custom-built as well.[2]: 12–13
See also
References
- ^ a b Iowa State University (2005). "Biosafety Cabinets". Retrieved April 24, 2010.
- ^ a b c d e f g h U.S. Centers for Disease Control and Prevention; U.S. National Institutes of Health (2000). Primary Containment for Biohazards: Selection, Installation and Use of Biological Safety Cabinets (PDF). U.S. Centers for Disease Control and Prevention.
- ^ University of Pennsylvania (November 6, 2009). "Clean Benches vs. Biosafety Cabinets". Retrieved April 24, 2010.