The CLP-B LABTEST Proficiency Testing Center began conducting proficiency testing and interlaboratory comparisons in 2004. The planning, organization, and implementation of each stage of the proficiency testing program are conducted in accordance with the requirements of the PN-EN ISO/IEC 17043:2011 and ISO 13528:2022 standards. The organizer's competence is confirmed by the accreditation certificate from the Polish Center for Accreditation – PT 003 , received in 2010. Thanks to its many years of experience, OBB CLP-B LABTEST is a renowned provider of proficiency testing, trusted by many previous participants..