US lawWashingtonRegulationsTitle 16 — AGRICULTURE, DEPARTMENT OFChapter 16-309 — CANNABIS LABORATORY ACCREDITATION STANDARDS PROGRAM16-309-270WAC 16-309-270WAC 16-309-270. Proficiency testingLast amended: 2024Year: 2026Length: 23 wordsOfficial source The laboratory must participate in an approved proficiency testing (PT) program that reflects the best available science as determined by the accrediting authority.PreviousWAC 16-309-260NextWAC 16-309-280