The American Chemistry Council (ACC)-sponsored Chemical Sector Emergency Preparedness Tabletop Exercise (TTX) provided a forum to facilitate discussion and document roles, responsibilities, processes, protocols, and systems used to support an effective public-private response to emerging all-hazard threats and incidents impacting the Chemical Sector. The TTX was meant to validate and provide feedback to enhance the recently developed draft Playbook for an Effective All-Hazards Chemical Sector Response (the “Playbook”). As a joint publication of the U.S. Department of Homeland (DHS) and the Chemical Sector Coordinating Council (CSCC),1 the Playbook is intended to provide a standard operating procedure to assist the Chemical Sector in preparing for, responding to, and recovering from all-hazards emergency events.