Glossary
What is a certificate of analysis (COA)?
If you have a hemp lab report in front of you, read along and check each section as you go.
A certificate of analysis is the lab's written record for one tested sample: who sent it, when it was tested and what the lab found. On hemp and CBD products, the parts that matter most are the cannabinoid results, including the delta-9 THC and total THC lines, and any safety panels for contaminants. This page walks through each section in plain English, decodes the units and lists the red flags to check before you trust a report.
What a certificate of analysis shows
Most hemp COAs follow the same basic layout:
- Header: the lab's name, address and license or accreditation, the client who sent the sample, the sample name, the batch or lot number and the dates the sample was received and tested.
- Cannabinoid potency: the amount of each cannabinoid tested, such as CBD, CBDA, CBG, CBN, THCA and delta-9 THC.
- Safety panels: results for heavy metals, pesticides, residual solvents, microbials (mold, yeast and bacteria) and mycotoxins. Not every report includes these.
- Moisture or water activity: common on flower reports, because it affects freshness and how results are calculated.
- Sign-off: the name or signature of the person who approved the results.
A report with only the potency section is often called a potency-only or cannabinoid report. A report with the safety sections is usually called a full panel.
How to read a hemp COA, section by section
| Section | What it tells you | What to check |
|---|---|---|
| Header | Who tested the sample, for whom and when | Lab name, license or ISO/IEC 17025 accreditation, report date, batch number |
| Cannabinoid potency | How much of each cannabinoid was found | CBD level matches the label; a delta-9 THC result is shown |
| Total THC | Delta-9 THC plus THCA, adjusted for weight | The figure used for legal limits |
| Heavy metals | Lead, arsenic, cadmium and mercury | Each result is below the limit, or marked Pass |
| Pesticides | Residues from crop chemicals | ND (not detected) or Pass |
| Residual solvents | Chemicals left over from extraction | ND or below the limit |
| Microbials and mycotoxins | Mold, yeast, bacteria and toxins from mold | Pass |
| Moisture (flower) | How dry the flower is | Within the range the lab lists |
Units and abbreviations: %, mg/g, ND and LOQ
Lab reports use a few units that are easy to decode once you know them:
- % and mg/g: potency is shown as a percentage of weight, in milligrams per gram, or both. One percent equals 10 mg per gram.
- mg per ml or per unit: some reports convert results for liquids or gummies. A 30 ml bottle labeled 1000 mg should test at about 33 mg per ml.
- Total THC: usually calculated as delta-9 THC plus 0.877 times THCA, because THCA loses some weight when it turns into THC. See our total THC definition.
- ND: not detected, meaning below what the lab's method can find.
- LOQ: limit of quantitation, the lowest amount the lab can measure with confidence. A result of less than LOQ means a compound may be present, but in an amount too small to measure precisely.
- ppm and ppb: parts per million and parts per billion, used for contaminants such as heavy metals and solvents.
Red flags to watch for
A COA is only useful if it is real, current and about the product in your hand. Watch for these warning signs:
- The batch or lot number on the report does not match the package.
- The report is years old, so it may not describe what is on the shelf today.
- The document comes from the manufacturer itself, or is marked provisional or for informational use only, but is presented as an independent test.
- There is no lab name, license or accreditation, or no way to contact the lab.
- Text looks edited, re-typed or pasted over, or a QR code does not lead to the lab's own website.
- A potency-only report is presented as proof of a full safety screen.
- The delta-9 THC line is missing or not quantified.
Third-party vs. in-house testing
A third-party lab is independent of the brand that made the product. That independence matters because a maker testing its own products has an obvious conflict of interest. Many state-licensed labs are also accredited to ISO/IEC 17025, an international standard for testing labs. Accreditation does not guarantee a result, but it does mean an outside body checks the lab's methods. You can read more under third-party lab testing.
Why COAs matter for THC and drug tests
Full spectrum CBD and all THC products contain THC, and even small amounts can add up. A COA tells you how much delta-9 THC and THCA a batch contained, which helps you understand legal limits and drug test risk. It cannot predict a drug test result for you. Our guide on whether CBD shows up on a drug test explains why.
How Tahoe CBD handles lab reports
We post third-party lab reports on our Lab Reports page when they are available. If you do not see the report for a product you are interested in, contact us and ask for it. We will send the most recent report we have for that product, or tell you plainly that it is not available yet. We do not present old reports as current results, and we encourage you to check the batch number and date on any report you receive, from us or anyone else.
Related terms
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