Little knowledge of biological safety cabinets, how much do you know?

1.
Biological safety cabinet The biological safety cabinet is the first-level safety isolation barrier for laboratory biological safety, and it is also the most critical safety protection equipment in the laboratory
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It is a negative pressure air purification fume hood to prevent the escape of dangerous biological aerosols during operation.
The main and key component of the biological safety cabinet is the air filter (HEPA)
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2.
What is the purpose of biological safety cabinets? It is used in various biosafety laboratories engaged in experimental diagnosis and the operation of infectious biological materials such as primary cultures, bacterial strains and other test samples.
It has safety protection equipment to protect operators, experimental environments and experimental samples
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3.
According to the design structure of airflow and isolation barrier, the safety cabinet is divided into several grades? It is divided into three grades: I, II, and III
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Class II biological safety cabinets are further divided into Type A and Type B.
Type A is further divided into Type A1 biological safety cabinets and Type A2 biological safety cabinets.
Type B is further divided into Type B1 biological safety cabinets and Type B2 biological safety cabinets.
4.
Class I biological safety cabinets Safety cabinets and their uses? Class I biological safety cabinets are used to protect personnel and the environment, and are biological safety cabinets that have no protection for the tested samples and can meet the requirements of hazard classes I, II, and III pathogenic factors
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The negative pressure air inhaled in the front window operation port protects the safety of personnel; the exhaust air is filtered by the filter and discharged to protect the environment from pollution
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Suitable for use where protection of the test sample is not required
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The air passing through the sample area is 100% exhausted into the laboratory environment after being filtered by the filter
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 　　Uses: Used as special sealing equipment (such as centrifugation, harvesting equipment or small fermentation equipment) or in operations that may generate aerosols (such as aerated culture or tissue stirring)
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Equivalent to a safety fume hood
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 　　5.
Class II biological safety cabinets and their uses? Class II biological safety cabinets are used to protect personnel, samples and the environment, and can meet the requirements of hazard classes I, II, and III pathogenic factors
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Safety cabinet with front window operation port, the operator can operate in the safety cabinet through the front window operation port, and the negative pressure air inhaled in the front window operation port protects personnel; the vertical descending air flow filtered by the filter protects the product; polluted air flow After being filtered by a filter, it is discharged to protect the environment
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 　　6.
Class II safety cabinets are classified according to the proportion of exhaust airflow to the total flow of the system and the internal design structure? Class II safety cabinets are divided into four types: A1, A2, B1, and B2 according to the proportion of the exhaust air flow to the total flow of the system and the internal design structure
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 　　7.
Class II A1 type biological safety cabinet and its use? The inlet air flow of the working window and the vertical air flow of the working area are mixed and then enter the cabinet at the upper part of the safety cabinet.
The average flow velocity of the air flowing into the front window operation port is 0.
40m/s; The gas is filtered by the filter and sent to the working area; the polluted air can be discharged to the laboratory after being filtered by the filter or discharged to the atmosphere through the exhaust pipe through the external exhaust interface of the safety cabinet.
70% of the gas is recycled and 30% is discharged.
To indoors or outdoors; the contaminated parts in the safety cabinet can be in a positive pressure state, and these positive pressure areas can be surrounded by no negative pressure areas
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It cannot be used for experiments with volatile toxic chemicals and volatile radionuclides
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 　　8.
Class II A2 biological safety cabinet and its use? The inlet air flow of the working window and the vertical air flow of the working area enter the box on the upper part of the safety cabinet after mixing
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The downdraft is a mixture of part of the inflow and part of the downdraft, which is filtered by a filter and sent to the work area
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After being filtered by the filter, the polluted air can be exhausted to the laboratory or to the atmosphere through the exhaust duct (soft connection) through the external exhaust interface of the safety cabinet
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70% recycled and 30% discharged
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 　　All polluted parts in the safety cabinet are under negative pressure or surrounded by negative pressure channels and negative pressure ventilation systems
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 　　Uses: When used for microbiological experiments with trace volatile toxic chemicals and trace radionuclides as auxiliary agents, it is necessary to connect a suitable exhaust hood
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The application is very extensive; the return air duct is negative pressure, and the gas discharged from the safety cabinet is introduced into the outdoors through the exhaust air duct, even if the exhaust air HEPA leaks, it will not cause danger to the operator
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 　　9.
Class II B1 biological safety cabinet and its use? The inlet air flow of the working window and the vertical air flow of the working area are mixed and then enter the cabinet at the top of the safety cabinet.
The average flow velocity of the inflow air from the operation port of the front window is 0.
5m/s.
After filtering, it is sent to the work area
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Most of the polluted downdraft is filtered by the filter and then discharged into the atmosphere through a dedicated exhaust pipe (hard connection); 70% of the air is filtered and discharged outside (required to be discharged outdoors), 70% of the outside air is supplemented, 30% The air is filtered and recycled
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 　　Uses: All biologically contaminated parts in the safety cabinet are under negative pressure or surrounded by negative pressure channels and negative pressure ventilation systems
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If the volatile toxic chemicals or radionuclides are circulated with the air and do not affect the experimental operation or the experiments are carried out in the direct exhaust area of ​​the safety cabinet, the B1 type safety cabinet can be used for trace volatile toxic chemicals and trace radionuclides as Microbiological experiment of auxiliary agent 10.
Class II B2 biological safety cabinet (full row type) and its use? The air flow in the working area is all from the laboratory or outdoors, and the exhaust air is directly discharged to the outdoors after being filtered by the filter.
The average flow rate of the air flowing into the front window operation port is 0.
50m/s; the downdraft is from the laboratory or outdoor air filtered by the filter.
(that is, the gas discharged from the safety cabinet is no longer recycled); the inflow and downflow are filtered by the filter and then discharged to the atmosphere through the special exhaust pipe (hard connection), and are not allowed to return to the safety cabinet and laboratory; 100% The airflow is filtered and discharged; 100% external air is supplemented; there is no circulating airflow
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 　　Uses: All polluted parts are in negative pressure state or surrounded by negative pressure channels and negative pressure ventilation systems for direct exhaust (not circulating in the work area)
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Type B2 safety cabinet can be used for microbial experiments with volatile toxic chemicals and radionuclides as auxiliary agents
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Suitable for samples of Biosafety Levels 1, 2, and 3
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