What a COA is
A Certificate of Analysis (COA) is the lab report that accompanies every cannabis product sold legally in Washington. WAC 314-55-101 requires every batch of flower, edible, concentrate, and topical to be tested by a state-certified lab before it reaches a retail shelf. The COA is the public-facing summary of that testing.
The full panel covers cannabinoid potency, moisture and water activity, residual pesticides, residual solvents (for concentrates), heavy metals, and microbiology (yeast, mold, E. coli, Salmonella). Different product categories trigger different mandatory tests, but the cannabinoid potency panel runs on everything.
How to find the COA
Every product sold in Washington carries a batch number printed on the label. That batch number is the key to its COA. Some processors post lab results directly on their website (searchable by batch number); some make them available at the retail counter on request. We can pull the COA for anything on our shelves — ask a budtender.
Reading the cannabinoid panel
The cannabinoid panel is the headline. For flower, the lines that matter most:
- Total THC — the load-bearing number. This is THCA + delta-9 THC adjusted for the chemistry that happens when THCA decarboxylates (heats up and turns into active THC). Total THC of 18% is mid; 22%+ is high; 28%+ is very high. Higher isn’t automatically better — terpenes and curing matter at least as much for the experience.
- THCA — the non-intoxicating acid form of THC found in raw flower. When you smoke or vape it, heat converts THCA into active THC. THCA itself doesn’t get you high until it’s heated.
- Delta-9 THC — the active form. In raw flower, this number is usually small; the lab math rolls it up into Total THC.
- CBD — non-intoxicating cannabinoid. CBD-heavy products land differently than THC-heavy ones — many people reach for CBD when they want a calming chemical without the head change.
- CBG, CBN, CBC — minor cannabinoids in small concentrations. Some products feature them; for most flower the numbers are <1%.
Reading the terpene panel
If the lab tested for terpenes (not every Washington lab does this on every batch), the COA will list the top terpenes by weight. A typical flower might be 2-3% total terpenes; high-terp strains hit 4%+.
Look at the top three and reference them against the terpene primer (myrcene, limonene, pinene, linalool, caryophyllene). The terpene profile shapes the experience more than the indica/sativa label.
The contamination panels
Washington labs test for:
- Residual pesticides — a fixed list of compounds; the COA shows "pass" or specific values. WAC sets the action limit; failing batches don’t reach the shelf.
- Residual solvents — for concentrates only. Butane, propane, ethanol, etc. The COA shows ppm values against the WAC action limits.
- Heavy metals — lead, arsenic, cadmium, mercury. Tested in concentrates and inhalables; values shown in ppm.
- Microbiology — total yeast and mold count, E. coli, Salmonella, Aspergillus. Pass/fail by category.
A "pass" stamp across these panels is the regulatory floor. If you ever want to see the actual values, the COA carries them.
Edibles specifically
For edibles, the cannabinoid panel reports both per-package and per-piece milligrams. A 100mg gummy bag with 10 pieces is 10mg per gummy — read the per-piece line, not just the total. WAC caps recreational edibles at 100mg total THC per package and 10mg per piece.