Participation in proficiency testing and the use of reference materials are important prerequisites for ensuring the quality of testing laboratories and their accreditation in accordance with the ISO / IEC 17025:2017 standard.

Laboratories are constantly striving to improve the quality of their procedures, tools and capabilities. No matter how carefully they conduct these internal audits, systematic discrepancies often go unnoticed. Therefore, it is important to compare their results with the results of other laboratories. Participation in interlaboratory proficiency testing schemes is a key criterion for accreditation, but it is also a significant investment in the reliability and operational certainty of the results provided.

Providing such services in the form of proficiency testing schemes or external quality control schemes (as they are mainly called in the medical field) is a conformity assessment service accredited with the ISO / IEC 17043:2010 standard.

ESYD has accredited a significant number of Greek Organizers of Interlaboratory Comparative Proficiency Testing that support the laboratory infrastructure of medical laboratories, food and water laboratories and building materials laboratories.