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Food Safety Focus (122nd Issue, September 2016) – Food Incident Highlight

Cancer Risk from 4-Methylimidazole in Soy Sauce is Low

Last month, a local survey found some soy sauce samples containing a possible carcinogen, 4-methylimidazole (4-MEI). During the manufacturing of permitted colourings caramel III and IV (used in soy sauce, cola-type beverages, beer, etc.), 4-MEI is formed as a trace impurity. 4-MEI may also be formed naturally when roasting coffee beans or meats. International food safety authorities consider the exposure level to 4-MEI from foods containing caramel III and IV does not give rise to health concern. Risk assessment has shown a 60-kg individual consuming up to 300 teaspoons of the soy sauce with the highest level of 4-MEI detected in the survey (15.9 ppm) every day will not reach the doses that can cause cancer in rodents.

Nevertheless, the Centre for Food Safety advises the manufacturers of caramel colours to maintain 4-MEI levels as low as technically possible and food manufacturers to use food colours with the lowest possible level required for the intended function. Consumers can look for caramel colours, caramel III and IV, or identification numbers (150, 150c, 150d) on the food labels to make informed choices.