Scientific Opinion on marine biotoxins in shellfish – Emerging toxins: Brevetoxin group

The EFSA Panel on Contaminants in the Food Chain (CONTAM Panel) assessed the risks to human health related to the consumption of brevetoxin-(BTX) group toxins in shellfish and fish. They are marine biotoxins which can accumulate in shellfish and fish. BTX-group toxins are primarily produced by the dinoflagellate Karenia brevis and cause neurologic shellfish poisoning (NSP). Symptoms and signs of NSP include e.g. nausea, vomiting, diarrhoea, parasthesia, cramps, bronchoconstriction, paralysis, seizures and coma. To date BTX-group toxins have not been reported in shellfish or fish from Europe and currently there are no regulatory limits for BTX-group toxins in shellfish or fish in Europe. The toxicological database for BTX-group toxins is limited, comprising mostly acute toxicity studies. In view of the acute toxicity and the lack of chronic toxicity data for BTX-group toxins, the CONTAM Panel considered that an acute reference dose (ARfD) should be established but due to the lack of data this was not possible. There is some evidence that BTX-2 forms DNA adducts. This raises concern about its potential carcinogenicity and consequential long term effects. Due to the lack of occurrence data on shellfish or fish in Europe, the limited data on acute toxicity and the lack of data on chronic toxicity, the CONTAM Panel could not comment on the risk associated with the BTX-group toxins in shellfish and fish that could reach the European market. The mouse bioassay (MBA) has traditionally been used to detect BTX-group toxins. However, due to poor specificity and ethical concerns it is not considered an appropriate method. In vitro and immunoassays have been developed as alternative, but they need further development. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods would be of value for the quantification of BTX-group toxins, but certified reference materials are needed to allow further method development and (interlaboratory) validation.