Biological safety cabinet selection can not bear the weight
Biological safety cabinets (BSCs) are the most basic safety protection devices in the laboratory biosafety first-class protective barrier and belong to Class III medical devices. The State Council’s Order No. 424 and the national standard GB19489-2004, which were issued in 2004, clearly stated that “biosafety cabinets are the main safety equipment necessary to protect workersâ€.
However, what is worrying is that at present, there are many problems in the understanding, selection and use of biosafety cabinets in the industry, which brings great hidden dangers to biosafety protection.
Inaccurate selection leads to unbearable weight
The biosafety cabinet protects the operator, the laboratory environment, and the experimental materials from exposure to the above operations in order to manipulate infectious materials such as primary cultures, bacterial strains, and diagnostic specimens. A product designed for the production of infectious aerosols and spills.
The structural design and exhaust ratio of the biosafety cabinet vary depending on the type of operating sample and the range of airspace that may be affected. According to this, the biosafety cabinet is divided into I, II and III, and the II is divided into A1, A2, B1 and B2.
Zhang Yaoxuan, senior engineer of the Shaanxi Blood Center and vice president of the Shaanxi Medical Device Industry Association Hospital Equipment Branch, stressed that the basic principle of biosafety cabinet selection is “suitableâ€. Laboratories of different safety levels should use biosafety cabinets of different grades and models, or they can be selected according to different types of protection and protection. In general, Class II B1 biosafety cabinets may be used when operating a small amount of volatile chemical reagents or radionuclides; Class II B2 biosafety cabinets must be used when handling large quantities of volatile chemical reagents or radionuclides. At present, the most widely used is the Class II A2 safety cabinet, which can fully meet the daily use of general general hospitals, energy saving and economical.
"Selection can not be advanced, the advance will be inaccurate, misalignment will bring unbearable weight." Zhang Yaoxuan said that in the case of the A2 can meet the application, blindly choose the B2 type, the problem will come. The B2 safety cabinet is 100% efflux, and the displacement can reach 1500 cubic meters per hour (different models). The exhaust volume of ordinary household exhaust fans is about 80 cubic meters per hour, which is more than ten times different. If the room does not have enough replenishment, the safety cabinet will not work properly. Open the laboratory door and do not meet the laboratory specifications. In addition, indoor air is discharged in a large amount, and it is necessary to ensure that the temperature in the laboratory satisfies the experimental requirements, and the load of the refrigerator and the heater is required to be very large. If the established laboratory cannot meet the requirements of indoor insulation and replenishment air volume, it will invest a lot of money to transform it, and the running cost will be high in the future.
Be cautious about publicity "selling point"
In recent years, there have been more and more brands of biosafety cabinets. Domestic brands include Suzhou Antai, Qingdao Haier, etc.; imported brands include Telstar in Spain, Thermo and Baker in the US, and Esco in Singapore.
Zhang Yaoxuan pointed out that in the face of the "selling point" of brand promotion, it is necessary to analyze it in detail. The choice of biological safety cabinet is first and foremost, followed by comparison of high-efficiency filters, air circuit design, alarm devices, negative pressure protection and other indicators. Installation, training and after-sales service are also very important. For example, usually electric and automatic control is a sign of the advanced nature of the equipment. However, the biosafety cabinet with electric front window should be analyzed in detail - there is no dual power supply system in the biosafety cabinet (or backup power supply that can be switched in time, or machine) In the case of internal delay power supply setting, if the power is suddenly lost, the electric front window will not be closed, which may cause harmful substances to leak and cause pollution. Moreover, the operating height is fixed whether it is a power window or a manual window. Therefore, this potentially dangerous electric front window function is of little value to general health facilities.
No clean bench can be used instead of safety cabinet
Some professionals have reported that some hospitals now use medical clean benches in places where biosafety cabinets should be used. Many operators believe that the two devices have the same shape and the same effect. The daily operation samples are ordinary samples and do not have high Pathogenicity.
In this regard, Zhang Yaoxuan emphasized that the biosafety cabinet and the clean workbench are essentially different: the clean workbench is a device that only protects the sample, and the purified air is blown down through the work area by the high-efficiency filter to protect the sample. Since the work area is a positive pressure zone, the airflow overflows through the operating window, so it does not protect the operator and the environment. If the sample contains known, unknown or potential pathogens, it is likely to cause harm to operators and the environment. In contrast, the biosafety cabinet is a vacuum filtration fume hood that emits gases that are rigorously filtered through a high-efficiency filter to protect the operator and the environment from harmful aerosols that are exposed during the experiment. in. Proper operation of the biosafety cabinet protects the operator, sample and work environment. Therefore, relevant medical units and laboratories that use clean benches instead of biosafety cabinets should reassess laboratory microbiological hazards. If there is a potential hazard to operators and the environment, the original clean benches should be replaced in time. Need to adapt to a suitable biosafety cabinet.
(Source: China Medical News)
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