Reading a COA: what the laboratory report says
The certificate of analysis (COA) is the most important proof of quality in CBD wholesale. For each batch it documents the cannabinoid profile, the THC content and the purity of a product. Here you will find what a COA contains, how to read it line by line, and why for retailers it decides both compliance and customer trust.
What is a COA (certificate of analysis)?
A COA, in full a certificate of analysis, is an independent laboratory report documenting the constituents of a specific product batch. It establishes in black and white what is actually in the product — from the CBD content through the THC value to contaminants and microbiological purity. A credible COA is not produced by the manufacturer but by an external, specialised testing laboratory.
The batch reference is decisive: every COA relates to one particular sample examined, and therefore to exactly the batch it came from. Since cultivation, harvest timing, extraction and further processing vary from batch to batch, a one-off certificate, or one covering several products, is inadequate. Only the current batch COA is binding.
In short: the COA is the independent evidence of a batch's identity, content and purity. The definition of the term is also in the COA entry in the glossary. At Hemp Wholesale Europe, every batch is available through the COA portal .
Which parameters does a COA cover?
A complete certificate of analysis covers two areas: the cannabinoid profile (active content) and the safety or purity testing. The overview below shows the most important parameters, what they tell you and what to watch as a buyer.
| Parameter | What it shows | What to watch |
|---|---|---|
| Cannabinoid profile | Content per cannabinoid (CBD, CBDA, CBG, CBN and others) as a percentage or in mg/g. | The declared CBD content matches the label. |
| THC content | The share of delta-9 THC (and sometimes THCA or total THC) in the batch. | Below the applicable limit; the central compliance figure. |
| Heavy metals | Contamination with lead, cadmium, mercury, arsenic. | Values below the maximum; marked as pass. |
| Pesticides | Residues of plant protection products in the raw material. | "<LOQ" or not detected; no exceedance. |
| Microbiology | Total count, yeasts, moulds, E. coli, salmonella. | Within the limits for the product category. |
| Residual solvents | Solvent residues from extraction (ethanol or butane, for instance). | Minimal with CO2 extraction; below the limit. |
| Mycotoxins | Toxins from moulds (aflatoxins, for instance). | Not detectable, or below the maximum. |
The cannabinoid profile is the heart of it: it lists every cannabinoid detected with its content. The THC value is the legally most delicate point. Residual solvents, in turn, are closely tied to the extraction method — clean CO2 extraction leaves practically no residue.
How to read a COA properly
At first glance a certificate of analysis looks like a desert of numbers. With a few reference points you can read it with confidence — from top to bottom.
Check the header
Laboratory name, accreditation, sample number, receipt and test dates. Without these, the document is worthless.
Match the batch number
The batch number in the COA must correspond exactly to the one on the product delivered.
Target values and limits
Every measurement is held against a maximum or limit value and usually assessed as pass or fail.
Understand LOD and LOQ
The detection limit (LOD) and quantification limit (LOQ) show from what value measurement begins; "<LOQ" or not detected means nothing of concern.
In practice, proceed like this: first check that the COA comes from an independent laboratory and carries a current date. Then match the batch number against the product. Next read the THC value — it must fall below the applicable limit — and confirm that every safety parameter (heavy metals, pesticides, microbiology, residual solvents, mycotoxins) is assessed as pass, or with values below the maximum. Only then compare the declared CBD content with the label.
A note on example figures: Numbers quoted in guides are always illustrations only. What binds is exclusively the real COA for your specific batch — never rely on example figures or last year's values.
Why the COA is critical for retailers
For B2B buyers the batch COA is far more than a marketing document — it is a tool for vetting suppliers and for legal protection. Four reasons make it indispensable:
THC compliance
The THC value in the COA establishes that the product stays below the statutory limit — the basic condition for legal trade.
Novel food relevance
For products taken orally the novel food regulation applies; a clean cannabinoid profile is part of your duty of care.
Protecting against liability
If a product is challenged, the batch COA is the evidence that you placed tested goods on the market.
Customer trust
Transparent, retrievable certificates of analysis convince resellers and end customers more than any piece of copy.
How to use the COA concretely in supplier selection, complaints and transparency towards end customers is covered in our EU compliance guide. Terms such as Novel Food and GMP are explained briefly in the glossary.
Checklist: recognising a credible COA
Not every document calling itself a certificate of analysis stands up to scrutiny. This checklist separates solid reports from worthless PDFs.
Warning signs: A missing laboratory or date, no batch number, a single blanket certificate for all products, missing contaminant values, or a THC result that sits suspiciously neatly at the limit — in such cases ask for a new, batch-specific COA.