Foodborne illness outbreaks attributed to chemical hazards in the United States, 2011-2025.

The Coordinated Outbreak Response and Evaluation (CORE) Network within the U.S. Food and Drug Administration (FDA) manages the investigation of multistate outbreaks of foodborne illness. From 2011 to 2025, CORE evaluated 1,270 foodborne illness incidents, of which 127 (10%) were attributable to a chemical exposure. Seafood toxins, from both shellfish and finfish, represented the majority of these incidents, followed by illicit or pharmaceutical drugs, toxic elements, and botanical toxins. Several case studies are presented which represent an array of classes of chemical hazards and distinct root causes of contamination. The detection and investigation of chemical foodborne incidents present additional complexities as compared to microbial outbreaks. These challenges include a lack of established surveillance and reporting systems for chemical incidents, difficulties in demonstrating a connection between illness presentation and a specific exposure to a given food product, and the heterogeneity of contamination. Additionally, many outbreaks require development and validation of new analytical methods for a novel food-contaminant pair to generate laboratory results sufficient to support regulatory action. FDA is committed to detecting, mitigating, and preventing chemical hazards in foods, including targeted public health surveillance programs, laboratory method development, and partnerships with other public health and food safety agencies to ensure a safe food supply for U.S. consumers.