oped. An examination of the general categories of chemicals and the chemical supply chain characteristics (Chapter 2) led to the identification of vulnerabilities (Chapter 3). A red teaming type exercise was then completed to determine ways in which the identified vulnerabilities could be exploited. All possibilities envisioned in this exercise were variations or combinations of a limited number of cases that required further examination. To demonstrate the adequacy, application, and plausibility of these cases and their potential consequences, general, illustrative scenarios were developed (Chapter 4). These scenarios utilized historical examples to illustrate the plausibility of the cases identified and their vulnerabilities, and to provide an existence proof of the possible consequences of not mitigating these vulnerabilities. Consideration of the scenarios and their consequences, and a detailed discussion of emergency management and risk mitigation (Chapter 5), led to the development of both general and specific science and technology recommendations created to guide DHS S&T initiatives (Chapter 6).