What does proficiency testing involve according to ISO 17025?

Proficiency testing, as defined by ISO 17025, specifically involves the evaluation of performance through interlaboratory comparisons. This process is designed to assess the testing capabilities of laboratories by having them analyze the same samples under defined conditions and then compare the results with those from other laboratories. This type of testing helps ensure accuracy and consistency in laboratory results, highlighting areas where improvement may be needed.

Unlike individual performance assessments or exclusive internal testing, proficiency testing emphasizes external validation and benchmarking against peers. It provides a means for laboratories to demonstrate their competence in performing specific tests and to enhance their credibility and reliability in the eyes of clients and regulatory bodies. This systematic comparison against a standard reinforces quality assurance in laboratory practices. Furthermore, proficiency testing is not about sampling without criteria; rather, it is a structured approach to validating analytical methods and results through collaborative evaluation among multiple laboratories.