These proficiency tests are organised at intervals determined by the reference laboratory depending on the difficulty of the methods used and the number of years since the network was set up. Testing is performed at a frequency of one to four tests per two-year period.

In practical terms, the reference laboratory prepares samples and sends them to the accredited laboratories for testing. The contents of the samples are, however, known only to the reference laboratory. The accredited laboratories then apply the official method and communicate their results to the reference laboratory. Any non-compliant results are discussed with the laboratories in order to identify changes that need to be made.

Inter-laboratory proficiency testing is organised in the fields of animal health, food safety, and plant health, for all National Reference Laboratory (NRL) mandates, including non-ANSES mandates.

Information on ILATs is available on LEILA, the online management and monitoring tool for Inter-laboratory Trials (ILTs), available at this address: leila.anses.fr.