Histamine

High levels of histamine may develop in a variety of fish species as they decompose. These species include tuna, mahi-mahi, marlin, bluefish, sardines, anchovy, bonito, herring and mackerel. Ingestion of histamine may cause scombroid poisoning in humans, which may lead to a variety of symptoms, including rash, nausea, vomiting, diarrhea, hypotension, palpitations and muscle weakness. Paralysis and death have also been reported in cases of scombroid poisoning. Because of its potential for human illness, the FDA has ruled that extensive refrigeration records and/or histamine testing must be included in a Hazard Analysis Critical Control Point (HACCP) program for relevant fish species. The FDA has set an action level of 50 parts per million (ppm) for histamine in domestic and imported fish.