Cannabinoids, THC, batch number, date and contaminants: a simple way to understand what a certificate of analysis actually tells you.
QUALITY & FLOWERS
The certificate of analysis, often called COA for Certificate of Analysis, is one of the most useful documents for checking a CBD product’s claims. A good COA links a sample to a date, a laboratory, a batch and measured results.
However, not all certificates cover the same elements. Some only cover the cannabinoid profile; others include pesticides, heavy metals, microbiology or residual solvents, depending on the product. The aim is therefore to understand what the document actually proves and what it does not.
The laboratory name and analysis date put the document in context. A very old analysis may be useful as an archive, but it does not necessarily describe a batch being sold today.
Look for an identifier linking the certificate to the batch. If the product page, label and document use different references without explanation, traceability becomes harder to verify.
A laboratory may analyse a flower, oil, resin or another product. The method and expected units are not necessarily the same. Checking the sample type prevents inconsistent comparisons.
The report may list CBD, CBDa, Δ9-THC, THCa, CBG, CBN or other cannabinoids. Columns often show a concentration, a detection limit or a “not detected” label.
Mass %, mg/g, mg/ml: two identical numbers do not necessarily mean the same thing. Before comparing, convert only if you understand the units and the matrix analysed.
Some reports show “total” values calculated from acidic and neutral forms. Do not recreate these calculations yourself if the laboratory already provides its method; read the document’s notes instead.
A cannabinoid certificate does not necessarily mean that every possible contaminant has been analysed. If there are separate pages for pesticides, heavy metals or microbiology, they should be clearly identified.
This check is particularly relevant for certain extracts made using solvents. For a flower or a solvent-free method, the analytical approach may differ.
Reports often use quantification and detection limits. “ND” does not necessarily mean absolute zero; it generally means the substance was not detected above the method’s limit.
A COA also helps check THC and overall consistency. Focusing on the most marketable figure misses the document’s main purpose.
An analysis from a previous harvest may illustrate a strain, but it does not replace testing of the batch being sold when precise values are claimed.
The laboratory measures what it is asked to test. It does not necessarily judge freshness, trimming or aroma. The COA complements the product assessment; it does not replace it.
Check: 1. laboratory, 2. date, 3. batch, 4. matrix, 5. units, 6. CBD/THC, 7. any contaminant tests. If these elements are clear, you already have a solid basis for checking a product page.
Also see the CBD / THC Analysis Guide and our article on CBD traceability.
Before even looking at cannabinoids, check that the sample name, batch number and date match the product concerned. A perfectly prepared certificate linked to another harvest does not provide the same information about the bag in your hands.
The cannabinoid table generally lists CBD, CBDA, THC, THCA and sometimes minor cannabinoids. Other pages in the same report may cover pesticides, heavy metals, microbiology or solvents. Not all COAs analyse the same parameters, so the first question is: “What was actually tested?”
More and more brands link labels to certificates using QR codes. This is convenient provided the document is readable, dated and linked to the current batch. Technology makes access easier; it does not replace consistent information.
It provides important analytical evidence, especially for composition, but does not replace assessing freshness, sorting and the actual product.
Usually “not detected” above the method’s detection limit. It does not necessarily mean complete absence.
Not necessarily. Check the pages and parameters analysed: contaminants may have separate reports.
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