CBD isolate: what 99% means on a certificate
A CBD isolate is cannabidiol purified until almost nothing but that one molecule is left: a white crystalline powder without terpenes or other cannabinoids. The "99%" printed on its certificate comes from chromatography and is given either as a percentage by mass or as a percentage of area, which are two different values. The THC detection limit, the residual solvents, the batch and the laboratory matter just as much.
Key takeaways
- Check the unit next to "99%": % by mass weighs the CBD, while % area only compares the peaks the detector sees.
- "THC not detected" means "below the detection limit", and the certificate has to print that limit.
- Crystallisation needs a solvent, so the residual solvent line tells you the most.
- EFSA's 2026 benchmark of 2 mg a day concerns CBD at least 98% pure, and it authorises no product.
- Phytogrammes does not sell isolate; this guide is for reading the certificates of the shops that do.
Definition: one molecule and nothing else
A CBD isolate is cannabidiol separated from the rest of the plant: minor cannabinoids, terpenes, flavonoids, waxes and chlorophyll. It is sold as a white powder or as crystals, and its certificates give 99% CBD or more. No form of cannabidiol is purer, and none is further removed from the hemp it was taken from.
CBD can be purified this far because it is a crystalline solid at room temperature, while a whole extract stays an oil or a resin. "CBD crystals", "CBD powder" and "CBD 99" are one product, sold in coarser or finer grains or named after its assay. Whatever the name, only the certificate of analysis tells you what the bag contains. The article full spectrum or isolate compares the two families as a user sees them; this one looks at the certificate.
How an isolate is made
The process has three steps, described here without parameters or equipment.
Extraction comes first. A solvent, usually supercritical CO₂ or ethanol, dissolves the compounds held in the trichomes. The crude extract still carries waxes, chlorophyll and every cannabinoid of the variety. The principle is set out in our article on supercritical CO₂ extraction.
Purification follows. Chilling the extract removes its waxes, a step called winterisation, and distillation or chromatography then separates the cannabinoids from everything else. The distillate obtained this way is rich in CBD, yet it still holds minor cannabinoids and part of the terpenes.
Crystallisation is the last step. The distillate goes into a solvent in which the solubility of CBD varies sharply with temperature. As the solution cools, CBD forms crystals and the other compounds stay dissolved; the crystals are then washed and dried. This is the step that lifts the assay past 99%. It also leaves a trace of the solvent in the powder, and the certificate has to measure it.
Isolate, broad spectrum, full spectrum: the table
| Criterion | Isolate | Broad spectrum | Full spectrum |
|---|---|---|---|
| Composition | CBD alone, 99% and above | THC-free extract, minor cannabinoids and terpenes partly kept | Whole extract: CBD, CBG, CBN, CBC, terpenes, flavonoids |
| Δ⁹-THC on the certificate | Not detected | Not detected or traces, depending on the removal method | Measured, 0.30% at most |
| Terpenes | None | Partly | Present, measured by GC-MS |
| Appearance | White powder or crystals | Amber oil or distillate | Oil, resin or flower, golden to brown |
| Lines to read first | Unit of the %, THC detection limit, solvents | THC removal method, solvents, terpenes | Cannabinoid profile, THC, terpenes, contaminants |
The article what full spectrum means defines full spectrum, and our guide to THC-free CBD oil covers broad spectrum. You read a whole extract's certificate for its profile. You read an isolate's certificate for the purity of one peak and for everything measured around it.
Reading an isolate certificate in five lines
Purity: percentage by mass or percentage of area?
Labs measure cannabinoid content by liquid chromatography with UV detection, or HPLC-UV. According to a 2025 review, it is the reference method in cannabis monographs in several pharmacopoeias. The molecules are separated on a column, and the area of the CBD peak is compared with a calibration curve drawn from a certified standard. That gives a percentage by mass, the grams of CBD in 100 g of powder, written % w/w or % m/m.
Some certificates print a "chromatographic purity" instead, as a percentage of area: the CBD peak's share of all the peaks detected. Anything the detector cannot see, such as water, a residual solvent or a mineral residue, is left out of that figure. An isolate may therefore show 99.8% area and a lower assay by mass. When a certificate says 99%, ask about the unit first.
Then ask about uncertainty, because even a validated HPLC method is not exact to the decimal. One validation published in 2022 reports recoveries of 100 to 105% for CBD, and its authors accept results that fall between 90 and 110%. Certificates reading 99.2% and 99.6% may well describe the same batch.
THC "not detected": a limit, not a zero
A well-purified isolate has no measurable THC, and its certificate has to show it. Yet "ND" (not detected) and "< LOQ" (below the limit of quantification) do not mean zero. ND says the method sees nothing and cannot look below a certain threshold; < LOQ says it sees something it cannot put a number on. A serious certificate gives both thresholds, the LOD and the LOQ, for every cannabinoid. When they are missing, "0% THC" is a label slogan with no result behind it.
French law allows up to 0.30% Δ⁹-THC in an extract. An isolate, however, is sold on the absence of THC, so any quantifiable THC level points to incomplete purification, whatever CBD percentage sits beside it.
Residual solvents: the line that separates certificates
The usual reference is the ICH Q3C (R9) guideline, written for pharmaceutical substances and published by the European Medicines Agency. It places solvents in three classes:
| Class | Examples | Limit |
|---|---|---|
| 1, to avoid | Benzene | 2 ppm |
| 2, to limit | Hexane; methanol | 290 ppm; 3,000 ppm |
| 3, low toxicity | Ethanol, pentane, heptane, 2-propanol, acetone | 5,000 ppm, or 0.5%, acceptable without justification |
You have three things to check. Does the solvent tested match the process? A certificate that looks only for ethanol tells you nothing about pentane. Is the method named? Residual solvents are measured by gas chromatography, usually in headspace (GC-HS). Are the values given as numbers? An "ND" for each solvent, with its detection limit, is worth more than a "compliant" line with no figure. Our article on solvents on a certificate reads resin certificates the same way.
Terpenes and contaminants
An isolate has no terpene profile, so an empty GC-MS panel is exactly what you should see. Terpenes on an isolate's certificate mean something was added, and the label must say so. Heavy metals (by ICP-MS), pesticides (by LC-MS/MS) and microbiology still have to be checked. A proper certificate reports a measured value for each of them.
Batch and laboratory
The certificate carries a batch number, a date and the lab's name. A "range" certificate without a batch binds no one. ISO/IEC 17025 accreditation attests that a testing laboratory is technically competent. In France it is granted by Cofrac, whose search engine for accredited bodies shows which labs hold it and for which analyses. An ISO logo on a shop's website is no substitute for that check, which our article on verifying a laboratory's accreditation walks through. For the other sections, see the guide how to read a certificate of analysis.
The French rules on isolate
Under the order of 30 December 2021, an isolate counts as a hemp extract: article 1 caps the Δ⁹-THC content of extracts, and of the products containing them, at 0.30%. The Conseil d'État, on 29 December 2022, struck down the ban on selling raw flowers and leaves and left that threshold untouched. An isolate with undetected THC sits far below it, but the rules for other extracts apply to it all the same.
Sold as a food, an isolate also comes under Regulation (EU) 2015/2283 on novel foods. Any food not consumed to a significant degree in the Union before 15 May 1997 needs prior authorisation. EFSA held 19 applications for CBD when it put their assessment on hold on 7 June 2022, citing a lack of sufficient data.
On 9 February 2026, EFSA published a provisional safe level of 0.0275 mg per kilo per day, roughly 2 mg for an adult of 70 kg. The benchmark applies to supplements of CBD at least 98% pure and free of nanoparticles, which is precisely the purity of an isolate. It authorises no product. On 20 May 2026, the French Ministry of Agriculture stated that foods containing CBD are illegal and have to be taken off the market. Our article on EFSA's reference dose and our update on the rules in 2026 go through these texts in detail.
Why isolate is not in the catalogue
Phytogrammes sells neither isolate nor CBD crystals. The catalogue is built on the whole plant, with flowers, resins and full spectrum oils, and each product page shows its cannabinoid profile. The page titled our laboratory explains what a reference profile shows and what it does not prove. Readers ask about isolate often enough that the question deserves an answer, and this guide gives one with nothing to sell.
Frequently asked questions
Not in any measurable amount, provided purification was done properly. The certificate then reads "not detected" or "< LOQ", meaning below the method's threshold, and that threshold must be printed on the document. A THC level high enough to quantify points to incomplete purification.
Yes. Both names refer to cannabidiol purified to 99% or more, in solid form. "Crystals" means larger grains and "powder" a fine grind, while "CBD 99" names the same product by its assay. You read the certificate the same way for all of them.
Purification removes them along with everything else that is not CBD, so an empty terpene panel is the result you should expect. A terpene profile on a product sold as isolate means something was added, and the label has to list it.
The benchmark is the ICH Q3C (R9) guideline: 5,000 ppm, or 0.5%, for class 3 solvents such as ethanol or pentane, 290 ppm for hexane and 2 ppm for benzene. A good certificate gives a figure for every solvent it tested.
Yes, as a hemp extract whose Δ⁹-THC content stays at or below 0.30%, under the order of 30 December 2021. Sold as a food, it also falls under Regulation (EU) 2015/2283, and in 2026 France authorises no CBD food.
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.