BioSafety Cabinet

Product description
In the biological safety protection equipment of the laboratory, in order to avoid the escape of pathogenic microorganism samples, chemical reagents and other substances to cause health hazards to the staff And to avoid cross-contamination of operating test objects, biological safety cabinets are the most important protective equipment. Therefore, the types, selection and use of biological safety cabinets have become extremely important topics for users. Biological safety cabinets are the main safety equipment used in laboratories. Through the high efficiency filter (HEPA) to remove harmful suspended particles to protect the safety of the operator and the environment in the experimental operating procedures. According to the NSF-49 classification, biological safety cabinets can be divided into three classes (CLASS).

Class I biological safety cabinet (CLASS I)
Similar to the chemical cabinet, the airflow enters from the front, and the exhaust air must be filtered by a HEPA filter. This equipment is provided for working operators and the general public. Protection. However, the research materials in such biological safety cabinets are susceptible to air pollution. Class I safety cabinets (CLASS I) are used to protect personnel and the environment, but they do not provide cleanliness for the experimental samples and products in the cabinet. protection. Therefore, the use of this level of safety cabinet is basically discouraged.

Class II biological safety cabinet (CLASS II)
According to NSF/ANSI 49 (2002) of the National Sanitation Foundation (NSF), it is subdivided into four types: A1, A2, B1 and B2, available The protection of the operator and the environment can also provide clean protection of the test products in the operation area. For example, when operating sterile animal tissues, cell culture, and virus propagation, such safety cabinets are required. The second-level biological safety cabinet adopts a special airflow design. After entering the operating area from the front opening, the external air is then guided into the circulation room without passing through test materials, providing a clean environment for aseptic operation. Because this type of biological safety cabinet can provide protection for the environment, personnel and samples at the same time, it is the most commonly used biological safety cabinet. The gas outlet of the safety cabinet of this level needs to be installed with HEPA, and the filtered air can be partially recycled (A1, A2 and B1) or fully exhausted (B2). The B2 biological safety cabinet can be applied to experiments of biological safety level one to three, and can be applied to volatile and toxic chemical substances. The two types of safety cabinets A1 and A2 are very similar. A1 type safety cabinet needs to provide a minimum surface velocity of 0.38 m/s, and A2 type safety cabinet requires a minimum surface velocity of 0.5 m/s. The A1 type fan is located under the cabinet, causing the gas passages in the cabinet to have positive pressure, so if the cabinet is slightly damaged, there is a risk of leakage. The ventilation mode of A1 and A2 safety cabinets is generally that 30% is exhausted by exhaust HEPA, and 70% is recycled by air supply HEPA.

Class III biological safety cabinet (CLASS III)
The timing of its use is to operate microbiological reagents classified as level 4 of biosafety, usually installed in controlled access, The strictest pollution control laboratory with special ventilation or special protection system. The inside of the safety cabinet needs to be a closed space with an air leakage rate of less than 10-5ml/sec and a closed observation window. For the safety cabinet where the sample is closed, it is taken through a immersion tank (which can pass through the safety counter ) Or an open box with double doors (such as a double-door sterilization pot). The supply and exhaust gas of this type of safety cabinet must be filtered by HEPA FILTER. When exhausting to the outside, the air pressure should be controlled by a dedicated independent exhaust system outside the safety cabinet to keep the safety cabinet under negative pressure at all times. The negative pressure is usually about 0.124 kPa. The experimental operation of this type of safety cabinet is carried out using sealed rubber gloves attached to the window of the safety cabinet to prevent users from direct contact with dangerous substances .

In order to ensure that the biological safety cabinet can perform its functions, in addition to choosing the correct cabinet type according to the experimental safety, the safety cabinet itself has various performances. Effectiveness testing is also very important, and not only the product safety certification when the biological safety cabinet is manufactured, but also the performance validation testing should be performed after the biological safety cabinet is installed and regularly to avoid the use of unqualified biological safety cabinets. Inappropriate use of biosafety cabinets may cause cross contamination of test objects (Cross Contamination) and affect the accuracy of the experiment. In severe cases, it may lead to personnel exposure, causing laboratory infection accidents, and even spreading severe epidemics.

Specification