Pharmaceutical Dust Collection with Hybrid Dust/Vapor Mix which is classified under a KH value instead of KST due to the addition of the flammable vapors. Venting is required in hybrid applications due to the vapor portion of the process on both the clean and dirty side of the dust collector since the vapor can pass through the filters and be present on both sides of the system. Isolation at the hopper is achieved through mechanical isolation means of a NFPA rated Rotary Airlock. Clean air is exhausted to atmosphere via ground mounted Cincinnati Fan so no isolation is required on that line. Chemical inlet isolation is required due to the return air isolation standard as outlined in NFPA 654, 7.1.3. IEP Technologies modeled and provided the design/solution to outfit a Donaldson Model DFE 4-16 Dust Collector with proper protection to meet NFPA requirements for the Hybrid Application.