Ranking methodology for risk-based monitoring of contaminants in the Norwegian Atlantic salmon production chain

In the European Union (EU), food safety is ensured through several measures, including risk-based official monitoring of contaminants in food and feed products. In Norway, the prioritization of contaminants to monitor in farmed fish, fish feed and feed materials has been based on expert judgement substantiated by e.g. scientific literature, legislation and information shared by other countries to the Rapid Alert System for Food and Feed (RASFF). However, a systematic approach for the prioritization would need to be established, ensuring risk-based monitoring of the Norwegian aquaculture production chain. In this study, a semi-quantitative scoring method was developed to rank contaminants for risk-based monitoring of farmed fish, fish feed and feed materials. The method includes the evaluation of the criteria on monitoring requirements set by competent authorities, occurrence data from the last five years of national monitoring programs performed in Norway, impact of the contaminants on human and animal health, and identifiable knowledge gaps. To evaluate the validity of the methodology, it was applied to selected contaminants relevant to the Norwegian aquaculture production chain. The approach is applicable across the entire farmed fish production process, from feed to fillet, and offers enhanced ranking resolution by assigning specific numerical scores to each contaminant. Additionally, it is suitable for assessing emerging contaminants, even when data availability is limited.