A biosafety cabinet (BSC) is a specialized piece of laboratory equipment designed to provide a controlled environment for handling hazardous or potentially infectious materials.

Here are the key points about biosafety cabinets:

1. Purpose: Biosafety cabinets are used to protect laboratory workers, the environment, and the materials being handled from exposure to infectious agents or hazardous particulates. They are commonly used in microbiology, clinical laboratories, pharmaceutical research, and other settings where biological safety is a concern.
2. Classifications: Biosafety cabinets are classified into different types based on their design and level of protection. The three main classes are Class I, Class II, and Class III cabinets, each providing different levels of protection for the user, the environment, and the material being handled.
3. Airflow: Biosafety cabinets use a combination of HEPA (High-Efficiency Particulate Air) filtration and directional airflow to create a sterile work environment. The airflow is designed to prevent the escape of hazardous aerosols and to provide a barrier against contamination.
4. Features: Common features of biosafety cabinets include a work area with a front opening for access, a HEPA-filtered air supply, a dedicated exhaust system, and a transparent window or shield for visibility. Class II cabinets may also have a built-in UV light for decontamination.
5. Protection Levels:
   • Class I cabinets provide personnel and environmental protection but do not protect the material being handled.
   • Class II cabinets provide personnel, environmental, and product protection and are further divided into Type A1, A2, B1, and B2, offering different levels of protection and exhaust systems.
   • Class III cabinets are gas-tight and provide maximum protection for personnel, the environment, and the materials being handled. They are typically used for working with highly infectious agents.
6. Applications: Biosafety cabinets are used for various activities, including cell culture, microbiological research, handling of infectious agents, drug compounding, and preparation of chemotherapy drugs.
7. Maintenance: Regular maintenance, including filter replacement, airflow verification, and decontamination procedures, is necessary to ensure the proper functioning of biosafety cabinets and to maintain a safe working environment.

In summary, biosafety cabinets are essential for providing a safe and controlled environment for working with hazardous or infectious materials. They offer protection for the user, the environment, and the materials being handled, and they play a crucial role in maintaining biological safety in laboratory settings. The specific type of biosafety cabinet chosen depends on the level of protection required for the materials and the activities being performed.