General safety information for cannabis Reading a Certificate of Analysis (COA)

A COA is a lab report that should accompany any legally sold cannabis product. Key things to check:

Matches the product — The COA should have a batch/lot number that matches the number printed on the actual package. A COA for a different batch (or no matching number at all) is a red flag.
Testing lab is named and licensed — Legitimate COAs list the actual lab name, address, and license number, not just a logo. You can usually verify the lab is real and accredited (look for ISO 17025 accreditation) by searching the lab name directly.
Cannabinoid potency panel — Should show THC, THCA, CBD, and often minor cannabinoids, with numbers that roughly correspond to what’s advertised. Wildly inflated potency claims (like unusually high THC%) without lab backing is a common counterfeit tell.

General safety information for cannabis

Contaminant screening panels — A full COA includes results for:
- Pesticides
- Heavy metals (lead, arsenic, mercury, cadmium)
- Residual solvents (from extraction — butane, propane, ethanol residue)
- Microbials (mold, yeast, E. coli, salmonella)
- Vitamin E acetate (specifically relevant for vapes, tied to the 2019 EVALI lung injury outbreak)
“Pass” on all panels — Each category should show a clear pass, not blank fields or “N/A” where a real result should be.
QR code verification — Many legal brands print a QR code linking directly to that batch’s live COA on the testing lab’s website. If the QR code doesn’t work, redirects somewhere unrelated, or isn’t present at all on a product that claims to be lab-tested, that’s a warning sign.

Compare against the brand’s official packaging — many legitimate brands post reference images on their official site specifically so consumers can compare. Look for font inconsistencies, color mismatches, or blurry logos.
Check for a state license number printed on the package (required in legal markets) and cross-reference it against that state’s cannabis regulatory agency database.
Look for security features — many licensed brands use holograms, unique serial numbers, or tamper-evident seals specifically to combat counterfeiting.
Inconsistent spelling or grammar on packaging is a common tell, especially for counterfeits produced overseas.
Price is a signal — prices significantly below typical dispensary pricing for a “name brand” product is one of the most common indicators of counterfeit product.

No mandatory testing — Unlicensed/gray-market sellers aren’t required to test for pesticides, heavy metals, or solvent residue, meaning harmful contaminants can go completely undetected.
Unregulated extraction processes — Illicit vape cartridges have been documented containing cutting agents like vitamin E acetate, which was directly linked to the 2019 EVALI (e-cigarette or vaping product use-associated lung injury) outbreak that caused thousands of hospitalizations and dozens of deaths in the U.S.
No batch accountability — If a legal product is found to be contaminated, licensed markets have recall systems tied to batch numbers. Unlicensed products have no such traceability, so contaminated batches can’t be tracked or pulled.
Hardware safety — Counterfeit vape hardware has also been found to use low-quality heating elements that can degrade and leach metals into the vapor at high temperatures.