Histamine Limits by Country: A Survey and Review.

Histamine is a biogenic amine and a food safety hazard, and it is the only biogenic amine regulated by statute or HACCP Guidance. This paper reviews the regulations for histamine levels in fish in countries around the world, including maximum limits or levels and sampling procedures in different fish preparations. The maximum histamine levels, sampling plans, and fish products are listed. The country-by-country regulations for maximum histamine acceptance levels in some food products vary by a factor of 8, from 50 ppm in some countries to a maximum of 400 ppm in other countries. For similar food products, the maximum histamine levels vary by a factor of 4 (from 50 ppm to 200 ppm) in, for example, fresh tuna. The country-by-country sampling plans vary widely as well and these, too, are covered in detail. Molecules of histamine are formed from L-histidine molecules, an amino acid, by a decarboxylation reaction caused by a bacterial enzyme, histidine decarboxylase. Histamine can form in many different species of saltwater fish that have elevated levels of free L-histidine. Histamine formation is completely preventable, and these methods are described as well. Although there are multiple maximum histamine acceptance levels, rapidly chilling the fish immediately after harvest by any means available is the only method to stop the formation of histamine. Fishermen should rapidly chill the fish using ice, chilled seawater, dense cold brine, or air blast freezers as quickly as possible.