These biological safety cabinets are designed to be hard ducted to the outside. During operation, room air is drawn into the top of the cabinet and through a supply HEPA filter. This filtered air flows downward through the work area. Room air is also drawn into the inlet grille located at the work access opening. All of the contaminated air passes through the exhaust HEPA filter. A dedicated exhaust system and remote blower discharge 100% of the filtered exhaust air from the laboratory. Since none of the air is recirculated, these biohazard cabinets may be used for work with agents treated with volatile toxic chemicals and radionuclides.