The bio-safety cabinet is used to protect the product, personnel, and the environment. Mostly it is used when risky microorganisms are handled. Most widely used Bio-Safety Cabinet is of class-II type A and B. Class-II A type Bio-Safety cabinets have partial exhaust i.e. 30% and 70% recirculation and class IIB type Biosafety cabinet has 100% exhaust. Class II B Biosafety cabinet is used when the most toxic or radioactive substances are handled.