WFSR report 2021.014 | 9 Summary National Reference Laboratories (NRLs) are part of the system responsible for the control and enforcement of EU food and feed law. Wageningen Food Safety Research (WFSR) has been designated as the NRL for thirteen subjects. The tasks of a NRL depend on its research fields. This report gives an overview of the activities performed by all of NRLs of WFSR in 2020. These NRLs are for: milk and milk products, marine biotoxins, animal proteins, certain substances and residues thereof as laid down in Directive 96/23/EC, additives for use in animal nutrition (feed additives), genetically modified organisms (GMOs) in food and feed, pesticides, metals and nitrogenous substances in feed and food, mycotoxins and plant toxins in food and feed, processing contaminants, halogenated persistent organic pollutants in food and feed, food borne viruses and water content of poultry. This report first gives an overview of relevant legislation and information on the networks of EURLs, NRLs and OLs. For every NRL, a description is then given of all activities performed in the EURL-NRL network such as participation in EURL-NRL workshops, working groups, and proficiency and comparative tests. This is followed by a description of the assistance given to OLs in the form of quality control and/or advice. Finally, the scientific and technical support given to the competent authority is discussed. In some cases, the contact with other NRLs is discussed. An important NRL task is to stay up to date with current developments within its NRL domain. Every EURL organises one or two meetings (workshops) every year for that purpose. Participation in these EURL-NRL workshops is mandatory. In 2020, due to COVID-19, most of these workshops were online. All workshops have been attended by NRLs of WFSR. Additionally, the NRLs have actively participated in EURL working groups, to improve analytical methods. To test the analytical capabilities of NRLs, the EURLs organise proficiency tests. Due to EURL proficiency tests sometimes being limited in their scope, the NRLs have also participated in proficiency tests organised by other organizations if thought to be relevant. Most results (z-scores) in these proficiency tests were good; only a few ‘questionable’ and a few ‘unsatisfactorily’ result were reported. Follow-up actions were implemented in those cases. The performance of the OLs has been assured by checking the results of their performance in proficiency tests (organised by other laboratories or the NRL) or by sending assurance-samples. Some OLs have also received technical support with regard to their analyses.