CBD concentrates compared 2026: what the certificate must show
Judge a hemp concentrate by the certificate for its batch; the product name proves nothing. Rosin and dry-sifted or water-washed hash use no solvent, while wax, crumble, live resin and most isolates do. For those extracts, the residual solvents line is the evidence that counts: in a 2015 study it revealed traces in 83.3% of the extracts tested.
Key takeaways
- What the certificate must contain depends on the process; a product made without solvent has no solvent line to show.
- Whatever the family, the certificate gives a batch number, a named laboratory, a date and a measured Δ⁹-THC below 0.30%.
- French and European law set no residual solvent limit for hemp extracts.
- A figure printed on a pouch measures nothing; in 2023, only 19% of products tested in France matched their label.
Four families, four processes
A concentrate is a resin-enriched fraction of the hemp plant, obtained by one of two routes. Mechanical separation uses cold, water or pressure to detach the trichomes, the resin glands. Extraction dissolves them in a solvent, which is then evaporated.
| Family | Process | Solvent | Certificate line specific to it |
|---|---|---|---|
| Rosin | Moderate heat and pressure on flower or hash | None | Not applicable |
| Sifted or water hash | Dry sieves or ice water, then pressing | None | Not applicable |
| Wax, crumble, budder | Extraction then vacuum purge | Butane, propane, ethanol | Residual solvents |
| Live resin | Extraction from fresh frozen plants | Butane, propane or other | Residual solvents |
| Isolate | Purification down to CBD crystals | Depends on the route | Purity and residual solvents |
According to a 2017 study in Drug and Alcohol Dependence, rosin is made by constant pressure at a moderate temperature, with no chemical solvent. A 2025 review in Frontiers in Toxicology separates butane extract from rosin in the same way. Each family has its own guide: CBD wax, rosin, crumble, live resin and 99% isolate.
The four items every certificate needs
A certificate is useful only if it carries four items, whatever the family.
- A batch number identical to the one on the packaging.
- The name of the laboratory and its ISO/IEC 17025 accreditation, the competence standard for testing laboratories. In France it is granted by Cofrac, which publishes the list of accredited bodies.
- The date on which the analysis was run.
- A cannabinoid profile measured by liquid chromatography (HPLC), showing Δ⁹-THC at no more than 0.30%.
Each accreditation covers a defined list of tests, called its scope. You can find it with our method to check a laboratory's scope, and the guide to the certificate of analysis takes each line in turn.
The residual solvents line, and what it has revealed
An extract made with butane, propane or ethanol should carry a residual solvents line, giving each compound tested, its limit of quantification and a numerical result. A blanket "compliant" with no list and no values gives you nothing to check.
Researchers have put numbers on the problem. In 2015, a team analysed 57 concentrates submitted by users in California, 48 solvent-based extracts and 9 dry or water hash samples. They found residual solvents in 83.3% of the extracts, isopentane most often, then butane, heptane, hexane and propane. Pesticides appeared in 19 samples, all of them extracts, and the 9 hash samples contained neither.
The samples date from 2012-2013 and come from a US market, so they say nothing about the French market today. What they show is why the line exists. How to read this section is explained in our article on solvents in CBD hash.
What limits apply to solvents?
For hemp extracts, no French or European text sets a residual solvent limit. The nearest framework is pharmaceutical: the ICH Q3C guideline, revision 9, in force since 29 April 2024, adopted by the European Pharmacopoeia, which sorts solvents into three classes.
| Solvent | ICH Q3C (medicines) | California (cannabis products) |
|---|---|---|
| Benzene | 2 ppm (class 1, to be avoided) | 1 µg/g |
| Hexane | 290 ppm (class 2) | 290 µg/g |
| Methanol | 3,000 ppm (class 2) | 3,000 µg/g |
| Ethanol, acetone, heptane, pentane | 5,000 ppm (class 3) | 5,000 µg/g |
| Butane, propane | Not in the tables | 5,000 µg/g |
One ppm is one µg/g. Butane and propane, the solvents most used for concentrates, are missing from every ICH table, while California's rules (4 CCR § 15718) cap them at 5,000 µg/g. None of these values applies in France. They give an order of magnitude when you read a foreign certificate.
Stated versus measured: the gap shows up on the batch
A figure on a pouch or in a product name is tied to no sample. A value on a certificate refers to a dated batch analysed by a named laboratory, and the two can differ widely. A study by French addiction-monitoring centres, funded by MILDECA, analysed 248 products bought in France in 2022 and 2023. Only 19% had a CBD content within 20% of the label, and 30 products exceeded the THC limit, at 0.4 to 1.2%.
Take an example from our catalogue of CBD resins and hash. On 23 September 2026, the Rosift CBG/CBD page showed 20.2% CBG, 4.6% CBD, 0.5% CBC, 0.4% CBN and 0.21% Δ⁹-THC for batch PG-26-3A2B. Keep the batch and the date with the figure, since a lone figure means little. What a reference profile shows, and what it does not prove, is explained on our laboratory page.
The French framework, and what Phytogrammes sells
The decree of 30 December 2021 authorises only those Cannabis sativa L. varieties listed in the official catalogues whose Δ⁹-THC does not exceed 0.30%. The same ceiling applies to extracts and to products containing them, concentrates included. On 29 December 2022, the Conseil d'État struck down the ban on selling raw flowers and leaves as disproportionate, leaving the threshold untouched.
Phytogrammes sells no solvent extract, so no wax, crumble, shatter, live resin or isolate. The pages of the 15 products in the resin category describe them as made without solvent, by dry sifting, ice water or pressing. They have no solvent line to show, and the four common items still apply to them.
Frequently asked questions
No. Rosin is made with heat and pressure, with no solvent at any stage. Everything else is still expected on its certificate: batch, accredited laboratory, date, cannabinoids by HPLC and Δ⁹-THC below 0.30%.
As a measurement, nothing: it is a sales claim. A 2023 study in France found that the CBD content matched the label in only 19% of the products tested. Ask for the batch, the laboratory and the date.
No limit is specific to hemp extracts. The benchmark most used is the ICH Q3C pharmaceutical guideline, which allows 5,000 ppm for class 3 solvents such as ethanol. Butane and propane are absent from it; California caps them at 5,000 µg/g.
Dry-sifted or water hash is made without them, and the 9 hash samples in the 2015 study contained none. A product sold as "hash" may still be a reworked extract, and only the solvent line on its certificate settles the question.
No. The products in the resin category are described as made without butane, propane, ethanol or CO2. This guide helps you read any certificate, including one for a concentrate bought elsewhere.
Written by the Phytogrammes team
Each journal article draws on cited primary sources: ANSM, EFSA, EUR-Lex and peer-reviewed publications. Product profiles are distinguished from documented laboratory results. Our approach.
Article published on . CBD is not a medicine.