How to choose a biological safety cabinet

Biosafety cabinet Knowledge Popularization: biosafety cabinet can be divided into three categories: first level, second level and third level to meet different biological research and epidemic prevention requirements The first level biosafety cabinet can protect workers and environment without protecting samples The principle of air flow is the same as that of laboratory fume hood, the difference is that HEPA filter is installed at the exhaust port All types of biosafety cabinets use HEPA filters at the exhaust and air intakes There is no fan in the first level biosafety cabinet, which relies on the fan in the external ventilation pipe to drive the air flow Because the sample in the cabinet cannot be protected, it is seldom used at present The secondary biosafety cabinet is widely used in Zui According to nsf49, the secondary biosafety cabinet can be divided into four different models: A1, A2 (original B3), B1 and B2 according to the inlet airflow speed, exhaust mode and circulation mode All secondary biosafety cabinets provide protection for personnel, environment and samples The airflow velocity Zui of the front window of type A1 safety cabinet shall be at least 0.38m/s in small quantity or average value 70% of the gas is recycled to the working area through HEPA filter, and 30% of the gas is filtered out through the exhaust port The airflow velocity Zui of front window of type A2 safety cabinet shall be at least 0.5m/s 70% of the gas is recycled to the working area through HEPA filter, and 30% of the gas is filtered out through the exhaust port The secondary B-type biosafety cabinets are all safety cabinets connected to the exhaust system The fan connected to the exhaust duct of the safety cabinet is connected to the emergency power supply, so as to keep the negative pressure of the safety cabinet under power failure, so as to avoid the leakage of dangerous gases such as the laboratory The airflow velocity Zui of the front window shall be at least 0.5m/s (100fpm) 70% of the B1 type gas is discharged through the HEPA filter at the exhaust port, and 30% of the gas is recycled to the working area through the HEPA filter at the air supply port Type B2 is a 100% full row safety cabinet without internal circulation air flow, which can provide biological and chemical safety control at the same time The third level biosafety cabinet is designed for the biosafety level of the fourth level laboratory The cabinet body is completely airtight The staff operate through the gloves connected to the cabinet body, commonly known as the glove box The test articles enter and exit the cabinet through the double door transfer box to ensure that they are not contaminated It is suitable for high-risk biological tests How to choose the biosafety cabinet (ordering Guide): Q: do I need to buy the biosafety cabinet or the super clean workbench? A: the super clean workbench provides the protection for the samples, but not for the operators and the environment; in a broad sense, the biosafety cabinet provides the protection for the operators, the environment and the samples at the same time Therefore, from the protection situation you need, you can get the right choice; Q: which type and protection level of biosafety cabinet should I buy a: Generally speaking, unless some unknown strains, viruses and live research need to use the three-level biosafety cabinet, the two-level biosafety cabinet can basically meet our normal work needs For the test of samples without toxic, radioactive and volatile irritant solvents, the A1 / A2 (original B3) biosafety cabinet has met the use requirements For the purchase of hospital system, because the types of viruses and bacteria are complex and the experimental conditions change greatly, it is recommended to use B2 full row biosafety cabinet Q: how to judge the quality of a biosafety cabinet A: biosafety cabinet is mainly used for biological hazard protection, so the protection consideration for operators is the main basis for judging the quality of products The core technology of the secondary biosafety cabinet Zui is filter membrane (including filter membrane material, filter membrane retention efficiency, filter membrane life), design of operation area and air path of the safety cabinet (including whether the working area of the safety cabinet is designed to be integrated with stainless steel plate, whether there are any screws or seams, whether the edge is processed by arc; balance of the front operation surface, settling wind speed, and uniformity and advancement of wind speed Air speed, vertical settlement form of wind), monitoring and alarm settings (a good biosafety cabinet should include real-time display of wind speed, low wind speed alarm, alarm of wrong position of front window, UV interlock device, B2 full row model also need to have external fan interlock device) and negative pressure protection (including side wall negative pressure, back negative pressure, top negative pressure) Therefore, we can know the advantages and disadvantages of the biosafety cabinet through the comparison of the above indicators; Q: why the balance of the front operating surface is an important indicator of a biosafety cabinet A: there is an open front operation surface in the secondary biosafety cabinet, which is convenient for operation and also brings a possibility of pollution If the balance is not good, the pollution in this area will be generated, so it is impossible to prevent the outside from entering the operation room to pollute the samples and the operator's protection from pollution discharge outside the operation room This is the essence of the design concept of the biosafety cabinet Therefore, the balance of the front operating surface of the secondary biosafety cabinet is very important In addition to understanding the performance indicators of the cabinet, the way to identify the safety performance of the cabinet is to know whether the cabinet you purchased has obtained the following major international certification: 1 Registration certificate (registration certificate of three kinds of medical devices in China); 2 Third party testing (each machine has a third party testing report); 3 Multiple certifications (appointment timing, remote control, foot switch, etc.); 5 After sales service (there are offices in key cities nationwide, covering most regions in China)