How to read a CBD certificate of analysis
An annotated sample certificate, point by point: what to check before you trust the CBD and THC figures a shop advertises.
Interactive guide · Free, no sign-up
Fictional certificate created for explanation. Click a blue number or any area of the document: the explanation appears alongside.
- Report no.
- CA-2026-10417
- Issued
- 14/10/2026
- Page
- 1 / 1
Client
Sample
- Product
- CBD flower Lemon Example
- Matrix
- Dried flower
- Batch
- L2610-B
- Received
- 08/10/2026
- Tested
- 10-13/10/2026
Methods
Cannabinoids
| Compound | LOD % | LOQ % | Result % | mg/g |
|---|---|---|---|---|
| CBDA | 0.003 | 0.01 | 9.80 | 98.0 |
| CBD | 0.003 | 0.01 | 1.20 | 12.0 |
| THCA | 0.003 | 0.01 | 0.25 | 2.5 |
| Δ9-THC | 0.003 | 0.01 | 0.04 | 0.4 |
| Δ8-THC | 0.003 | 0.01 | ND | ND |
| CBGA | 0.003 | 0.01 | 0.32 | 3.2 |
| CBG | 0.003 | 0.01 | 0.15 | 1.5 |
| CBN | 0.003 | 0.01 | < LOQ | < LOQ |
| CBC | 0.003 | 0.01 | 0.08 | 0.8 |
| CBDV | 0.003 | 0.01 | < LOQ | < LOQ |
| THCV | 0.003 | 0.01 | ND | ND |
| Total CBD | 9.79 ± 0.98 | 97.9 | ||
| Total THC | 0.26 ± 0.03 | 2.6 | ||
| Total cannabinoids | 11.84 | 118.4 |
Moisture: 9.2 %. Results expressed on the product as received.
Expanded uncertainty (k = 2): ± 10 % of the value.
Heavy metals
| Parameter | mg/kg | Reference | |
|---|---|---|---|
| Lead (Pb) | < 0.05 | 0.50 | ✓ |
| Cadmium (Cd) | 0.07 | 0.50 | ✓ |
| Mercury (Hg) | < 0.01 | 0.10 | ✓ |
| Arsenic (As) | < 0.05 | 0.20 | ✓ |
Pesticides
Microbiology and mycotoxins
| Parameter | Result | Reference | |
|---|---|---|---|
| Total aerobic count | 2.1 × 10³ UFC/g | 10⁵ | ✓ |
| Yeasts and moulds | 4.0 × 10² UFC/g | 10⁴ | ✓ |
| Escherichia coli | < 10 UFC/g | 10² | ✓ |
| Salmonella (25 g) | Absent | Absent | ✓ |
| Aflatoxin B1 | < 0.5 µg/kg | 2 | ✓ |
| Total aflatoxins | < 1 µg/kg | 4 | ✓ |
| Ochratoxin A | < 2 µg/kg | 20 | ✓ |
Check your certificate
0 / 10Open the certificate of the product you are interested in and tick each point you have checked.
Label or certificate?
-Compare the CBD level advertised by the seller with what the certificate lets you calculate.
For information only. It does not replace legal advice or a lab analysis.
What a certificate of analysis is for
The certificate of analysis (COA) is the document an independent lab issues after testing a sample. It is the only serious proof of a CBD product's cannabinoid content. A figure on a product page without a certificate is just the seller's claim.
The five key checks
First, the lab: its name should be readable and ideally it should be accredited to ISO/IEC 17025, the standard for testing labs. Second, the batch number: it must match the batch on sale, otherwise the certificate describes another product. Third, the date: an analysis more than a year old rarely describes current stock. Fourth, the method: liquid chromatography (HPLC) measures acid forms (CBDA, THCA) and neutral forms (CBD, THC) separately, so totals can be calculated. Finally, the totals: total CBD and total THC, calculated with the 0.877 factor.
Understanding the abbreviations
LOQ stands for limit of quantification: below it, the compound may be present but in too small an amount to measure. ND means not detected. mg/g and % express the same thing: 10 mg/g = 1 %. For oils, results may be given in mg/ml.
Warning signs
Be wary of a certificate with no lab name, no batch number, a blurry or cropped image, or one that shows only Δ9-THC without a THCA line. Many labs let you check a certificate online with a QR code or an ID. For flowers and resin, extra tests (pesticides, heavy metals, mould) are a real plus.
Got the numbers? The total THC calculator does the maths for you.
FAQ · 3 questions
Frequently asked questions
Short, clear answers with no health claims.
What does COA mean?
COA stands for certificate of analysis, the document a lab issues after testing a sample.
What does < LOQ mean on a certificate?
The compound is below the lab's limit of quantification: it is absent or present in too small an amount to measure reliably.
Is one certificate valid for every batch?
No. It only describes the batch that was tested. The batch number on the certificate must match the product you buy.
Big CBD Product is an independent, non-profit comparison site. Our answers follow a public method: verified data, dated reviews and no disguised advertising. See our method