Washington Cannabis Testing Overview
COA Requirement:
Required.
All cannabis and cannabis products must be tested by a certified laboratory, and a Certificate of Analysis (COA) must be issued before the product is transferred or sold.
Cannabinoid Testing:
Required.
Labs must test for:
- Δ⁹-THC
- THCA
- CBD
- CBDA
- Total THC = Δ⁹-THC + (0.877 × THCA)
- Total CBD = CBD + (0.877 × CBDA)
- Any marketed or labeled THC variants (e.g., Δ⁸-THC, THCV)
Terpene Testing:
Not required.
Terpenes are not included in the mandatory COA panel in Washington.
Contaminant Testing:
a. Pesticides:
- Over 60 compounds must be tested
- Examples:
- Myclobutanil (≤0.2 ppm)
- DDVP (≤0.1 ppm)
- Paclobutrazol (≤0.4 ppm)
- Bifenthrin (≤0.2 ppm)
- All other unlisted or disallowed pesticides: action level = 0.1 ppm
- If failed: product must be destroyed; pesticide remediation is not permitted
b. Heavy Metals: Required for Department of Health (DOH) compliant products; optional for others, but limits apply to all:
- Arsenic: ≤2.0 ppm
- Cadmium: ≤0.82 ppm
- Lead: ≤1.2 ppm
- Mercury: ≤0.4 ppm
c. Mycotoxins:
- Aflatoxins (B1–G2): Total ≤20 µg/kg
- Ochratoxin A: ≤20 µg/kg
d. Microbial Contaminants:
- Shiga-toxin-producing E. coli and Salmonella: Not detected
- Bile-tolerant gram-negative bacteria:
- Flower: ≤10⁴ CFU/g
e. Foreign Matter: Fails if:
- ≥5% stems ≥3 mm diameter
- ≥2% seeds or foreign matter
- Any insect, hair, or mammalian excreta present
Contaminants Not Required (But of Concern):
- No terpene testing
- Listeria monocytogenes and Shigella spp. are not explicitly required
- Chromium and Nickel not listed in the metal panel
- No USP 1111 compliance or herbal monograph used for microbiological validation
Risk Level:
Low Concern:
Washington enforces one of the most rigorous and specific pesticide, solvent, and microbial panels in the U.S. Retesting and remediation allowed only under strict rules.
Moisture and Water Activity:
Required.
- Flower: ≤0.65 aw
- No stated moisture content threshold for flower
State Cannabis Regulatory Agency:
Washington State Liquor and Cannabis Board (WSLCB)
Website: https://lcb.wa.gov
Phone: (360) 664-1600
Address: P.O. Box 43098, Olympia, WA 98504
Email: enforcement@lcb.wa.gov
References:
Washington State Legislature. (October 25, 2019). WAC 314-55-108 Pesticide Action Levels.
Washington State Legislature. (March 12, 2022). WAC 314-55-102 Quality assurance and quality control.
Washington State Liquor and Cannabis Board. (2025, January 7). WAC 314-55-102: Quality Assurance and Quality Control and WAC 314-55-108: Pesticide Action Levels