Methemoglobinemia is an unusual and potentially fatal condition in which hemoglobin is oxidized to methemoglobin and loses its ability to bind and transport oxygen. The most common cause of methemoglobinemia is the ingestion or inhalation of oxidizing agents such as nitrates or nitrites (e.g., sodium nitrite, which is used commonly as a preservative in curing meats and fish). This report summarizes the investigation of an incident of methemoglobinemia in five members of a household in New York who became ill after eating a meal seasoned with a white crystalline substance from a plastic bag labeled "Refined Iodized Table Salt" (Figure). The findings underscore the need for proper storage of hazardous materials to avoid unintentional ingestion and the importance of collaboration by multiple agencies to address a potential public health emergency.