A certificate of analysis is written in laboratory shorthand, and a handful of terms decide what it actually says. This glossary defines them in a sentence or two each: batch code, limit of quantitation, not detected, HPLC, total THC, contaminant panel and accredited laboratory, with a link to the full explanation of every one.
Editorial Team · Compliance and product research · Updated
Most of the confusion around certificates comes from a small number of terms read loosely: a "not detected" read as zero, a total cannabinoid figure read as a THC figure, a product name read as a batch. Each definition below is short enough to keep beside a certificate while you read it.
| Term | What it means |
|---|---|
| Certificate of analysis | A laboratory report of what was measured in a sample from one batch, by which method, and when. Often shortened to COA. See how to read a certificate of analysis. |
| Batch code | The code that identifies one production run. It links the object in your hand to a laboratory record; a product name does not. See what a batch code is. |
| Test date | When the laboratory sampled and reported. Material changes after testing, so an old date on current stock is a gap in the record. See why a test date matters. |
| Accredited laboratory | A laboratory an independent body has assessed against ISO/IEC 17025 for its methods, equipment, staff competence and quality systems. See what an accredited laboratory is. |
| ISO/IEC 17025 | The international standard for the competence of testing and calibration laboratories. Accreditation against it is not a licence to sell anything. |
| Term | What it means |
|---|---|
| HPLC | High-performance liquid chromatography. It separates a sample without heating it, so acidic forms such as THCA are reported apart from delta-9 THC. See how cannabinoids are measured. |
| Gas chromatography | A method that heats the sample, converting acidic forms on the way through, so THCA and delta-9 THC cannot be reported separately. |
| Limit of quantitation | The smallest amount a method can put a reliable number on, often written LOQ. A certificate should state it for each line. |
| Limit of detection | The smallest amount a method can distinguish from nothing, often written LOD. It sits below the limit of quantitation. |
| Not detected | Below the laboratory limit, written ND. It does not mean zero: a method with a lower limit might report a number for the same sample. |
| Dry weight basis | A figure calculated as though all moisture had been removed from the sample, so wet and dry material can be compared. |
| Term | What it means |
|---|---|
| THCA | Tetrahydrocannabinolic acid, the form the plant makes. Heat converts it to delta-9 THC. See what THCA is and what heat does to it. |
| Delta-9 THC | The neutral form that THCA becomes on heating, reported as its own line on a certificate made by liquid chromatography. |
| Decarboxylation | The loss of a carboxyl group when an acidic cannabinoid is heated. It is what turns THCA into delta-9 THC, and CBDA into CBD. |
| Total THC | Calculated, not measured: 0.877 multiplied by THCA, plus any delta-9 THC already present. See total THC and how the number is worked out. |
| Total cannabinoids | The sum of every cannabinoid measured. It says the material is cannabinoid-rich in general, and nothing specific about THC. |
| CBN | Cannabinol, what THC becomes as it degrades in heat, light and air. A raised figure points to age or poor storage. See CBD, CBG, CBN and the minor cannabinoids. |
| Term | What it means |
|---|---|
| Contaminant panel | Everything a certificate tests beyond potency: heavy metals, pesticides, residual solvents, microbials and mycotoxins. See what a contaminant panel covers. |
| Heavy metals | Metals a plant takes up from soil and water, usually reported as lead, arsenic, cadmium and mercury. |
| Residual solvents | Solvent left behind by processing, reported in parts per million. |
| Microbials | Living contamination, reported as counts of bacteria, yeast and mould. |
| Mycotoxins | Compounds produced by moulds rather than the moulds themselves, usually aflatoxins B1, B2, G1 and G2, and ochratoxin A. |
| Action limit | The level a result is judged against. A pass means below that limit, on that sample, on that date, and nothing wider. |
| Term | What it means |
|---|---|
| Printed potency | A figure on a box with no batch record behind it. It is a claim, not a measurement. See why potency belongs on a certificate, not a box. |
| Process words | Terms such as live resin, distillate and rosin describe how material was made, not how strong it is. See live resin, distillate, rosin and liquid diamonds. |
| Counterfeit | A copy of a branded device, usually with a batch code that leads nowhere. See spotting a counterfeit device and reading a product label. |
Certificates are not posted publicly on this site. Licensed resellers receive the official certificate for a batch on provision of their licence, and other buyers can request a summary of the batch record. Both are requested against the batch code printed on the package, as described on the lab results page.
Sold to adults 21 and over. This article explains the subject in general. What any particular product contains, and in what quantity, comes from the certificate of analysis issued against the batch code on its packaging — not from an article, not from a product page, and not from anything printed on a box.
Part of our guide: How to Read a Certificate of Analysis
A certificate describes material as it was on one day. Cannabinoids convert and degrade, terpenes evaporate, and CBN rises with age. A figure from eight months ago describes eight-month-old material, so the date is part of the measurement rather than an administrative detail.
Laboratories separate a sample into its components and measure each one. Liquid chromatography keeps acids intact and reports THCA and delta-9 separately. Gas chromatography heats the sample, converting acids on the way through. Which method was used changes what the numbers mean.
A printed figure is fixed at the moment the packaging was designed. A certificate is measured for one batch on one date. When the two disagree the certificate is the one that describes what you actually have, which is why a figure on a box should be treated as a claim rather than a measurement.
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