The overall objective of this study is to assess vulnerability of the food supply to introduction of a chemical or biological contaminant through a food additive. To our knowledge, no group has performed a vulnerability assessment that considers the intentional contamination of food additives. The feasibility of food contamination through additives is supported by epidemiological reports characterizing disease outbreaks resulting from consumption of manufactured foods accidentally contaminated with Salmonella spp. bacteria from spice additives. The proposed study will be accomplished by first using quantitative methods to identify additives that are commonly consumed because they are in a great number of foods or because they are in the most commonly consumed foods. Additives will be defined as those ingredients listed in FDA's Everything Added to Food in the United States database. Next, we will identify contaminants with sufficient toxicity to kill or injure people at very low doses, and which would survive food manufacturing processes. Contamination will then be modeled, both in highly consumed foods and foods that contain additives with high prevalence of use, to identify foods in which specific additive/contaminant combinations would result in casualties. Additive production process, additive use in manufacturing and additive characteristics will be researched and modeled to determine the extent to which contamination of an additive can impact the food supply. This study will fill a critical gap in our understanding of the vulnerability of the food supply to intentional contamination and will inform the development of systems to protect the food supply through prevention, detection, response, and recovery.