The BioSafety Cabinet (BSC) is used to operate equipment for biological hazards, harmful chemicals, radioactive substances and other substances. Through the negative pressure air filtration system, it can ensure that there is no leakage of high-risk material experiments. It is usually divided into three levels: Level I means that the discharged gas does not need to be filtered; Level II means that the discharged gas must be filtered; Level III is a sealed negative pressure glove box.