The biological clean safety cabinet (biosafety cabinet) can protect samples and staff. The filtered clean airflow is blown down from the top of the safety cabinet through the working area for the staff to breathe. In this post, we will share with you something about biological safety cabinets.
The air in the cabinet will be filtered and discharged back to the laboratory or exhausted to the outside. Youthtech is a professional cleanroom supply manufacturer in China since 2005.
The working principle of the biological safety cabinet
The working principle of the biological safety cabinet is mainly to suck the air inside the cabinet to maintain a negative pressure in the cabinet and protect the staff through the vertical airflow. The outside air pass through a high-efficiency particulate air filter (HEPA).
Then enter the safety cabinet to avoid contamination of the processed samples; the air in the cabinet also needs to be filtered by a HEPA filter before being discharged into the atmosphere to protect the environment.
The Classifications of the biological safety cabinets
For biological research and different requirements, there are three levels of biological safety cabinets.
1.Biological safety cabinet class 1 can protect staff and the environment without protecting samples.
The airflow principle is the same as a laboratory fume hood, except for the exhaust port with a HEPA filter. All types of biological safety cabinets use HEPA filters at the exhaust and intake ports. It has no fan itself and relies on the fan in the external ventilation pipe to drive the airflow. Since it cannot protect the samples in the cabinet, it is out of time at present.
2.Biological safety cabinet class 2 is currently the most widely used cabinet type.
In the NSF49, according to the inlet air speed, exhaust mode, and circulation mode, there are four different models of biological safety cabinet Class 2: A1 and A2 type, B1 and B2 type. All biological safety cabinets class 2 can provide protection for staff, the environment, and samples.
3.Biological safety cabinet class 3 is designed for the laboratory biological safety level 4.
The sample passes through the pass box, enters, and exits the safety cabinet to clean it. The biological safety cabinet class 3 is suitable for high-risk biological experiments.
Principles for using the cabinets in biosafety laboratories
When the laboratory level is level 1, there is no need to use a biological safety cabinet or use biological safety cabinet Class 1.
When the laboratory level is level 2, microbial aerosols or spills may occur. Use biological safety cabinet class 2 when handling infectious materials. If it involves handling chemical carcinogens, radioactive substances, and volatile solvents, should use the biological safety cabinets Class II-B with full exhaust.
When the laboratory level is level 3, should use biological safety cabinet Class 2 or Class 3, all operations involving infectious materials should use a fully exhausted type II-B level (B2 type) or biological safety cabinet Class 3.
When the laboratory level is level 4, should use biological safety cabinet class 3 with full exhaust. When researchers wear positive pressure protective clothing, they should use the biological safety cabinet Class 2.