FDA Issues Final Compliance Policy Guide for Scombrotoxin (Histamine)-Forming Fish and Fishery Products

The U.S. Food and Drug Administration (FDA) announced the availability of a final Compliance Policy Guide (CPG) intended to provide the FDA’s current thinking on the adulteration of fish and fishery products with scombrotoxin (histamine). 

The CPG, titled “Sec. 540.525 Scombrotoxin (Histamine)-forming Fish and Fishery Products – Decomposition and Histamine (CPG 7108.24) Compliance Policy Guide,” will assist the FDA in addressing adulteration associated with decomposition and histamine identified during surveillance sampling and testing. It also will increase consumer protections related to scombrotoxin (histamine) fish poisoning (SFP) by lowering the levels of histamine in fish at which the FDA indicates that it may take action.

The composition of the muscle tissue in certain fish species, such as tuna and mahi-mahi, can cause histamine and other spoilage compounds to form due to the activity of enzymes produced by spoilage bacteria after a fish dies, which can then lead to scombrotoxin fish poisoning. Unless fish are properly chilled, histamine can accumulate and once formed cannot be removed by washing, freezing or heating. However, histamine can be easily controlled and mitigated by applying basic good hygienic practices, such as rapidly chilling fish and maintaining appropriate time and temperature controls. Properly harvested and handled fish and fishery products have little to no detectable histamine. 

Scombrotoxin fish poisoning continues to represent the highest number of illnesses associated with finfish in the United States. Symptoms include tingling or burning in or around the mouth or throat, rash or hives on the upper body, drop in blood pressure, headaches, dizziness, itching of the skin, nausea, vomiting, diarrhea, asthmatic-like constriction of the air passage, heart palpitations and respiratory distress. 

Consistent with the available scientific evidence, the FDA has concluded that lowering the histamine criteria for decomposition from two or more sample units at 50 ppm or greater to one or more sample unit at 35 ppm or greater is appropriate because histamine at that level indicates significant decomposition and mishandling of the fish. Additionally, adoption of a 200-ppm histamine level based on the possibility of human illness at or above that level is consistent with the conclusions of a 2013 FAO/WHO report and aligns the U.S. with other nations.

This CPG represents the most substantive update on the issue in nearly 30 years. In December 2021, the FDA published a draft CPG and asked for public comment. The final CPG supports the agency’s public health goal of reducing foodborne illness in the U.S., specifically scombrotoxin fish poisoning.