The Mt. Zion Hospital Pharmacy’s two new ventilating hoods require sufficient exhaust or else a fail-safe system will register a malfunction and equipment will automatically shut off. This is where chemo chemicals are prepared so it is critical that all air borne particles be exhausted from inside the hoods via connecting ductwork that leads outside the building. Even after meticulous construction that included manual sealing of all 300 feet of twisting ductwork, the exhaust system was simply not providing enough pull to meet code or to keep the system running properly.