CBD certificate of analysis: 6 lines to read on a COA

A certificate of analysis is a measurement: a laboratory received a sample, prepared it, ran it through an instrument and reported numbers. It describes only that sample, taken from one batch, on one date. It is neither a label nor a brand guarantee.

Three consequences for the reader. A certificate for another batch says nothing about the pouch in your hand. An old certificate says nothing about a flower that has aged since, because THCA slowly turns into THC and then CBN during storage. And a "range" certificate with no batch number is tied to no product at all.

No French rule requires a certificate to be published. The limit, however, is fixed: the order of 30 December 2021 caps the Δ⁹-THC content of authorised hemp varieties at 0.30%, and sets the same cap for "hemp extracts, and the products that contain them". The certificate is the only document that puts a figure against that limit.

Start with the header. The batch number must match the one printed on the pack, character for character. Note the date the sample was taken or received, then the report date. For a flower, a report more than a year old deserves a question to the seller.

The laboratory must be named, with an address and a report number. The words "ISO 17025" are not enough: that standard sets competence requirements for testing laboratories, but it is accreditation that confirms a laboratory meets them for defined tests. In France, Cofrac is the only body allowed to grant these accreditations. Its directory publishes each laboratory's scope, meaning the exact list of tests covered. Our guide to checking the scope of an accreditation walks through it in five steps.

Finally, look at the method. For cannabinoids, liquid chromatography (HPLC) separates the acidic and neutral forms and quantifies each one. Gas chromatography (GC) heats the sample: a 2022 study shows that the injector temperature decarboxylates acidic cannabinoids, so a GC result blends THCA and THC. A certificate that does not name its method leaves you guessing what it measured.

Hemp makes THC in an acidic form, THCA, which becomes THC when heated. An HPLC certificate therefore shows two lines: Δ⁹-THC and THCA. To add them up, THCA is corrected for the mass it loses when it becomes THC. The 0.877 factor is the ratio of the molar masses, 314.5 g/mol for THC and 358.5 g/mol for THCA.

A fictional example, to show the arithmetic. A flower reads 0.12% Δ⁹-THC and 0.25% THCA. Its total THC is 0.12 + 0.877 × 0.25, or 0.34%. The Δ⁹-THC line is under the limit; the total is not. And the annex to the 2021 order sets out a gas chromatography test for varieties, whose heat turns most of the THCA into THC during the measurement. Our article on THCA explains this reading, and the one on the 0.3% limit covers the official method.

The same calculation applies to CBD. A flower with 1.1% CBD and 9.8% CBDA contains 1.1 + 0.877 × 9.8, or 9.7% total CBD. Check which convention the certificate uses for its "total" line: a plain sum of 10.9% would overstate the content.

The list of molecules tested matters as much as the results. A certificate that only quantifies CBD and THC says nothing about semi-synthetic cannabinoids. The ANSM, the French medicines agency, listed HHC, HHCO and HHCP as narcotics from 13 June 2023, then H4CBD, THCP and other derivatives from 3 June 2024. The same page states that THCA is excluded when the THC content complies with the 0.3% limit. THCA in compliant hemp is therefore not banned.

On a product sold as CBD, look for these molecules on the list. If they are missing from the list, they were not tested for, which does not mean they are missing from the product. Our article on synthetic cannabinoids explains why this check matters.

A complete certificate adds contaminant panels. The main ones:

For pesticides, the European Commission notes that a default limit of 0.01 mg/kg applies when a substance is not named in the tables. Solvents only concern extracts made with a solvent: a sieved or ice-water resin contains none by design.

That leaves the small results. "ND" (not detected) means the instrument saw nothing above its limit of detection. "< LOQ" means the molecule may be present, but below the limit of quantification, the smallest amount the method measures with validated accuracy. Both limits are among the characteristics a method must establish under the ICH Q2(R2) guideline. An "ND" with no numeric limit does not tell you from what amount the instrument would have seen anything.

If in doubt, write to the laboratory with the report number: only it can confirm that it issued the document. Our page on how a sample moves through our laboratory describes each step, and the CBD laboratory page covers the measurement methods.

A compliant level offers no protection behind the wheel. On 21 June 2023 (no. 22-85.530), France's Court of Cassation ruled that the authorisation to sell products at 0.30% THC does not prevent prosecution: driving after using a narcotic is an offence whatever the dose. Since the law of 9 July 2025, the penalty is up to 3 years in prison and a €9,000 fine. The certificate tells you how much THC the product contains, not what a saliva test will detect. Our drug testing guide covers the details.