This paper reports a computational fluid dynamics (CFD) study on containment of airborne hazardous materials in a ventilated room containing a downdraft table. Specifically, we investigated the containment of hazardous airborne material under a range of ventilation configurations. The desirable ventilation configuration should ensure excellent containment of the hazardous material released from the workspace above the downdraft table. However, increased airflow raises operation costs, so the airflow should be as low as feasible without compromising containment. The airflow was modeled using Reynolds Averaged Navier Stokes equations with a high Reynolds number k-epsilon turbulence model using the commercial CFD code StarCD. CFD predictions were examined for several ventilation configurations. Based on this study, we found that substantial improvements in containment were possible with a significant reduction in airflow, compared to the existing ventilation configuration.