A biosafety cabinet is a negative pressure filtration exhaust cabinet designed to protect operators, laboratory environments, and experimental materials from the impact of infectious aerosols and splashes that may occur during the operation of infectious experimental materials (such as primary cultures, bacterial strains, and diagnostic specimens). The following is a detailed introduction about biosafety cabinets:
Structure and Principle
1. Cabinet structure: usually composed of a box body, an operating console, a front panel, an air filtration system, a fan system, a lighting system, an ultraviolet lamp sterilization system, and other parts.
➸Box body: Generally made of stainless steel material, it has good corrosion resistance and robustness, providing support and protection for other components of the biosafety cabinet.
➸Operating table: Made of high-quality physical and chemical plates or stainless steel materials, the surface is smooth and flat, easy to clean and disinfect, and convenient for experimental operations.
➸Front panel: It is usually made of transparent tempered glass or acrylic sheet, which is convenient for operators to observe the operation process and has a certain protective effect.
2. Working principle: Indoor air is mainly drawn in by a fan through the front panel air inlet, filtered by a high-efficiency particulate air filter (HEPA), and evenly sent into the work area along the vertical or horizontal direction, thereby forming a stable and clean airflow barrier in the work area. This airflow barrier can effectively prevent external polluted air from entering the work area, while also timely discharging aerosols and harmful gases generated during the operation process, protecting the safety of operators and the environment.
Classification and Characteristics
1. First level biosafety cabinet: does not protect samples, protects personnel and the environment. The principle of airflow is the same as that of a laboratory fume hood, except that the exhaust port is equipped with a HEPA filter. All types of biosafety cabinets use HEPA filters for exhaust and intake. The first level biosafety cabinet itself does not have a fan and relies on the fan in the external ventilation duct to drive the airflow. Due to the inability to protect the products inside the cabinet, it is currently rarely used.
2. Secondary biosafety cabinet: It is currently the most widely used type of biosafety cabinet. It can protect workers, the environment, and products, and can be used for microbial experiments with trace volatile toxic chemicals and trace radioactive nuclides as auxiliary agents. Secondary biosafety cabinets can be divided into four levels based on intake flow rate, exhaust method, and circulation method, namely A1 type, A2 type, B1 type, and B2 type.
➸A1 type: Air enters from the front window operating port, flows through the surface of the workbench, and is directly discharged from the opposite exhaust port without circulation. Its characteristics are simple structure, easy operation, and suitable for general microbial experiments.
➸A2 type: The intake method is the same as A1 type, but after passing through the surface of the workbench, a portion of the air will circulate back to the workspace through the HEPA filter, while the other portion will be discharged. This design can improve air utilization efficiency, reduce energy consumption, and ensure the cleanliness of the workspace.
➸Type B1: The intake air passes through the front window operating port, and after passing through the surface of the workbench, most of the air will circulate back to the workspace through the HEPA filter, with only a small portion being discharged. Applicable to experiments involving microorganisms or harmful substances that pose a significant threat to human health.
➸B2 type: Air enters from the front window operating port, flows through the surface of the workbench, is completely discharged, and does not circulate. This type of biosafety cabinet can provide the highest level of protection and is suitable for handling highly pathogenic microorganisms or conducting high-risk experiments.
3. Level 3 biosafety cabinet: designed according to the highest biosafety protection level, suitable for laboratories with biosafety protection level 4 and extremely high operational risks. The cabinet is completely sealed, and staff can operate it through gloves connected to the cabinet. It can detect pathogens such as Ebola virus.
Suzhou Pharma Machinery Co.,Ltd.
2025/04/07
Alice
