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Application scope of Class II safety cabinet

日期:2020-09-28 16:58
浏览次数:48
摘要:Class II safety cabinet application scope _ the working principle of class II safety cabinet is mainly used for clinical diagnosis, teaching and to group related to serious diseases in the broad spectrum of endogenous moderate risk factors operate experiments. Class II B2 type safety cabinet can also be used for volatile toxic chemicals and the radioactive nuclide is complementary to auxiliary micro experiments. If the potential risk of levitation from these pathogens is low, these mi
Class II safety cabinet application scope _ the working principle of class II safety cabinet is mainly used for clinical diagnosis, teaching and to group related to serious diseases in the broad spectrum of endogenous moderate risk factors operate experiments. Class II B2 type safety cabinet can also be used for volatile toxic chemicals and the radioactive nuclide is complementary to auxiliary micro experiments.



If the potential risk of levitation from these pathogens is low, these microarrays can be safely operated on an open platform using sophisticated microtechnologies. Hepatitis B virus, human immunodeficiency virus, Salmonella, toxoplasmosis are the microrepresentatives of this level of protection. Class II safety cabinets are suitable for workplaces where contact with human blood, body fluids, tissues or primitive human cell lines with unknown source of infection exists.



Major risks to persons exposed to these sources at work may include occasional skin or viscose exposure or ingestion of these infectious substances, with particular attention to injuries caused by contaminated needles or sharp instruments. Even though microspheres frequently operated in a class II safety cabinet cannot be transmitted as aerosols, they must be carried out in a class I protective cabinet or in a device such as a safety cabinet or in a safe centrifugal cup, because aerosol or spillage may occur during operation, increasing the risk of human exposure. Other primary barriers available are splash shields, face shields, robes and gloves.







When the fan is started, the air flow into the cabinet from the previous working area is called the incoming flow, and contains the air aerosol generated during the micro-experiment operation. The incoming flow will be inhaled into the incoming gas fence network at the front of the working platform close to the operator. No unfiltered airflow enters the actual work area of the safety cabinet, so there is no need to worry about contamination of samples. The unique feature of the safety cabinet is that inside the cabinet there is a vertical descending air layer (air curtain airflow) after being filtered by HEPA. The continuously descending air layer will take away all the pollutants in the air inside the cabinet, thus protecting the experimental samples from pollution. This descending air layer is called descending gas (downward airflow).



When the descending air flow is relatively close to the working table, it will be divided into two strands, one of which enters the air fence net behind the cabinet, and the other air flow is sucked into the air fence net close to the operator *. All the gas in the cabinet is taken as a whole, with one part discharged out of the cabinet through the HEPA filter and the other part circulating in the cabinet as a downdraft after being filtered through the HEPA. Because the air flow inside the cabinet is always in the negative pressure state, so the operator and the environment are not exposed to harmful substances, suitable for safety standard one, two, three reagents work.