In mid-1973, the Michigan Chemical Corporation accidentally shipped bags of FireMaster—a toxic flame retardant composed of polybrominated biphenyls (PBBs)—instead of NutriMaster, a magnesium oxide cattle feed supplement. The toxic chemical was mixed into feed distributed to thousands of farms across the state. Over the following months, farm animals displayed horrifying symptoms including hair loss, deformed hooves, and organ failure.
Because PBBs are fat-soluble synthetic compounds that resist metabolic degradation, they bioaccumulated exponentially up the food chain. Contaminated meat, milk, butter, and eggs entered the consumer food supply long before authorities realized the mistake. It is estimated that over eight million Michigan residents ingested PBBs, leading to long-term health monitoring, increased cancer risks, and persistent biological burden passed down across generations.