(a) The laboratory shall participate in a proficiency testing program (“PT program”) provided by an organization that operates in conformance with the requirements of ISO/IEC 17043, at least once every six months after receiving ISO/IEC 17025 accreditation. (b) The laboratory shall participate in the PT program by following the laboratory’s existing SOPs for testing cannabis and cannabis products. (c) The laboratory shall rotate the PT program among the analytical methods in the laboratory’s scope of accreditation and among the employees who perform the test methods. (d) Laboratory employees who participate in a PT program shall sign the corresponding analytical reports or attestation statements to certify that the PT program was conducted in the same manner as the laboratory tests of cannabis and cannabis products. (e) A supervisory or management laboratory employee shall review and verify the accuracy of results reported for all PT program samples analyzed. (f) The laboratory shall provide PT program results to the Bureau within 3 business days after the laboratory receives notification of their test results from the PT program provider. Authority: Section 26013, Business and Professions Code. Reference: Sections 26100 and 26110, Business and Professions Code.