Selection, Use and Interpretation of Proficiency Testing (PT) Schemes by Laboratories (2021)


ptguide2011_132This document represents the current state-of-the-art with respect to the selection and use of proficiency testing schemes, and the interpretation of results and evaluations given in proficiency testing schemes. Although aimed primarily at staff in analytical laboratories, it is also useful for customers of laboratories, assessors working for accreditation bodies and other external users of PT scheme results.

The main topics covered by the Guide are:

  1. the aims and benefits of participation in PT schemes;
  2. selecting the most appropriate PT scheme;
  3. understanding the basic statistics and performance scoring used by the PT providers;
  4. using and interpreting the PT results in order to improve the overall performance of the laboratory.

This third edition, approved in 2021, brings the guide up to date with standards and guidance documents that have been revised and developed since the second edition was released in 2011. In particular it aligns the guide with ISO 13528:2015 and with current guidance on developing a PT participation strategy and selecting the most appropriate PT schemes.

The third edition was prepared by the EEE-PT Working Group (EA-Eurolab-Eurachem). EQALM (European Organisation for External Quality Assurance Programmes in Laboratory Medicine) as an affiliate member was also involved in this revision.


This Third Edition is currently available in English and can be downloaded at no cost from the link below.


Note 1: Third edition first published on this website on 2021-03-02. Dates above are the date of publication of the particular document on this website.

Note 2:The present English version, designated EPT 2021:P2,  is a second print to correct a minor error identified in the first printing. Corrections can be found in the list of errata available from this page.


This guidance should be cited* as
"B. Brookman and I. Mann (eds.) Eurachem Guide: Selection, Use and Interpretation of Proficiency Testing (PT) Schemes (3rd ed. 2021). Available from"

*Subject to journal requirements.


Translation into other Eurachem Member languages is permitted for members of Eurachem, subject to the Eurachem Policy for development of guidance, available on our Policies page.

Translation by other organisations is only permitted with prior written permission. Other organisation should approach the Eurachem Secretariat or the Working Group Secretary.

Previous editions

Earlier editions of this guide are available in the publication archive on this website.


The version of the documents available at the links above are the latest print available and may include minor editorial corrections since first publication of the Third Edition in the relevant language. A complete list of these changes is provided for reference at the link below.