Biosafety cabinets fitted with HEPA filtered air flow system with unidirectional constant flow of air with almost no or minimal turbulence. The air flow velocity remains between 0.4 m/s to 0.6 m/s. The purpose of using such workstations in laboratory is to create particle and bacteria free working environment to carry out specialized work. As these units discharge air towards user, they provide no personal protection but product protection from room contaminants