The EFSA Panel on Contaminants in the Food Chain (CONTAM Panel) has prepared a series of opinions since 2007 on various marine biotoxins, including emerging toxins, to assess the current European Union (EU) limits with regard to human health and methods of analysis as established in the EU legislation. In order to protect high consumers against acute effects of marine biotoxins, the CONTAM Panel identified 400 g of shellfish meat as an appropriate estimate of a large portion size consumed in Europe to be used in the risk assessments. This portion size was then applied to all the scientific opinions on marine biotoxins. Recently EFSA has received new data from Belgium, France, Portugal and Spain on the shellfish portion sizes consumed. In addition, new consumption data have been submitted to EFSA for inclusion in the Comprehensive European food consumption database (Comprehensive Database). Based on the assessment of the new data provided to EFSA and the information included in the EFSA Comprehensive Database, the CONTAM Panel concluded that the earlier established estimate of the consumption figure of 400 g shellfish meat is appropriate for protecting high consumers against acute effects of marine biotoxins.