Washington cannabis testing requirements

Required tests

• Potency
• Pesticides
• Residual solvents
• Heavy metals
• Microbials
• Mycotoxins
• Water activity
• Foreign matter

ISO/IEC 17025 accreditation

Not required. Labs must be accredited by the Washington State Department of Agriculture to the state standard in chapter 16-309 WAC and certified each year by the LCB. Neither rule requires ISO/IEC 17025.

Notes

• Rules: WAC 314-55-101 (sampling), 314-55-102 (quality control testing, last amended effective 24 May 2025) and 314-55-0995 (lab certification). Lab standards: chapters 16-309 and 16-310 WAC.
• WSDA took over cannabis lab accreditation from the LCB in July 2024 under HB 1859 (2022); labs must use WSDA-approved methods and approved proficiency-testing providers.
• Flower: water activity (0.65 aw max), cannabinoids, foreign matter, microbials, mycotoxins and pesticides.
• Extracts: cannabinoids, mycotoxins and pesticides, plus residual solvents for hydrocarbon, CO2, ethanol and food-grade-solvent extracts. Solid edibles: cannabinoids and water activity (0.85 aw max).
• Microbials: bile-tolerant gram-negative bacteria (10,000 CFU/g unprocessed, 1,000 CFU/g processed); STEC and Salmonella under 1 CFU/g.
• Mycotoxins: total aflatoxins B1, B2, G1 and G2, and ochratoxin A, 20 µg/kg each.
• Foreign matter fails at 5% stems 3 mm or wider, 2% seeds or other matter, or one insect fragment, hair or mammalian excreta.
• Heavy metals (arsenic, cadmium, lead, mercury) are required only for DOH-compliant products (chapter 246-70 WAC); the limits apply to all products and the LCB may test at random.
• Terpene analysis is optional.
• Pending: LCB rulemaking on heavy metals testing, R&D testing and certificate-of-analysis expiry is at the pre-proposal (CR-101) stage.
• The Department of Health runs the medical cannabis authorization database and sets DOH-compliant product standards.