The U.S. Food and Drug Administration (FDA) has issued a draft Compliance Policy Guide (CPG) that amends the current CPG Sec. 540.525 on decomposition and histamine in fish and fishery products. The draft CPG provides guidance to assist FDA in addressing adulteration associated with decomposition and/or histamine identified during surveillance sampling and testing. It also adds consumer protections related to histamine poisoning by lowering the levels of histamine in fish at which FDA indicates that it may take action.

Due to the composition of the muscle tissue in certain finfish species, such as tuna, mahi-mahi, and sardines, decomposition after the fish die can produce histamine, which can threaten human health. Unless properly chilled after death and maintained in a chilled state, or otherwise treated or processed to prevent further microbial activity, histamine can accumulate in the edible muscle of these fish. Once formed, histamine cannot be reliably removed by washing, freezing, or heating. 

Poisoning can occur within a few minutes to several hours after ingestion of fish that contains high levels of histamine. However, when properly harvested and handled, these fish have little to no detectable histamine levels. Histamine poisoning, or Scombrotoxin fish poisoning, continues to represent the highest number of illnesses associated with finfish in the U.S.

FDA is updating two guidance levels for the presence of histamine in these types of fish:

• If samples have 35 parts per million (ppm) or more histamine (lowered from 50 ppm), FDA may consider the fish to be adulterated because they are decomposed and/or produced under insanitary conditions.  
• At 200 ppm (lowered from 500 ppm), FDA may consider the fish to be adulterated based on the presence of a deleterious substance (histamine) that may render them injurious to human health. 

The CPG notes that elevated histamine levels can be prevented in fish by adherence to Current Good Manufacturing Practices and Hazard Analysis Critical Control Point principles required by FDA’s Fish and Fishery Products regulation by each processor in the distribution chain.

The updates to this CPG bring the agency’s regulatory position and thinking in line with current science and increase public health protection.