Human health risk assessments are used by environmental regulatory agencies to determine risk from Hazardous Air Pollutants (HAPs). In this study, the Human Exposure Model (HEM-3) was used to compare the cancer and non-cancer inhalation health effects of a single organic chemical manufacturing facility in Geismar, Louisiana prior to and after Maximum Achievable Control Technologies (MACT) were implemented. The results indicate significant reductions in both cancer risk and non-cancer hazards. The analysis also indicated that the equivalent cancer risk reduction could have been achieved by addressing MACT in only one production process and one single pollutant (ethylene dichloride) within that process. This demonstrates the value that these risk assessments have at evaluating emissions at the facility level, and how they could be used in the control strategy decision making process.