Grumman/Butkus Associates completed two separate designs for a major pharmaceutical client that required facilities for handling potent compounds. Potent compounds are active in relatively low doses or concentrations; extreme caution must be taken in every aspect of the design and in the construction of a potent drug handling facility. Systems and construction materials are selected and applied to best protect the lab occupants and the environment from the effects of the compounds, as well as from chemicals and materials used for cleaning. Each facility is ultimately subjected to the scrutiny of the Food and Drug Administration in accordance with current Good Laboratory Practices (GLP). The HVAC systems were commissioned, qualified, and validated.