Prioritizing veterinary drug residues in animal products for risk-based monitoring

The EU Official Controls Regulation (EU) 2017/625 (OCR) requires a risk-based monitoring program for veterinary drug residues in animal products. The aim of this research was to rank various substances in animal products as input for such a Multi-Annual National Control Plan (MANCP). Previously derived decision trees were used to prioritize a total of 438 substances and 5228 substance-product combinations. The prioritization incorporated information on non-compliances, use of veterinary drugs and potential human health effects. Overall, the majority of the unauthorised substances (63%) were classified as high priority, although there are distinct differences between substance groups. For the authorised substances, around 27% were classified as low priority, 17% as medium priority and 12% as high priority. For the remaining substances, there was a lack of data resulting in the recommendation to start a survey. The evaluation revealed that not all relevant substance-product combinations are currently included in the MANCP and data or information on (potential) use is often difficult to retrieve. Overall, the decision trees provided a successful tool to classify substances in low, medium and high priority to include in the MANCP and the approach could be applied by other EU MS as input to their risk-based monitoring programs.