If you are researching live resin, liquid diamonds, THC vapes or cannabis concentrates, you have probably come across the term COA.
COA stands for Certificate of Analysis. It is a laboratory report that provides analytical information about a particular sample or batch.
For consumers comparing cannabis products, a COA can be useful because it can provide information that packaging and marketing claims cannot establish on their own. Depending on the product and testing laboratory, a report may include cannabinoid concentrations, terpene information and testing for contaminants such as pesticides, heavy metals, microbial contaminants or residual solvents.
This is particularly relevant when comparing live resin and liquid diamonds, because the product name alone does not tell you exactly what is in the formulation.
In this guide, Sluggers Carts explains how to read a live resin or liquid diamonds COA, what the most important sections mean, how to match a report to a product and which red flags to look for. Learn our Liquid Diamonds and Live Resin Vape UK
What Is a COA?
A Certificate of Analysis (COA) is a laboratory document reporting the analytical results obtained from testing a particular sample.
For cannabis and cannabinoid products, a COA may contain information about:
- Cannabinoid concentrations
- THC and THCA
- CBD and other cannabinoids
- Terpenes
- Residual solvents
- Pesticides
- Heavy metals
- Microbial contaminants
- Sample identification
- Batch or lot number
- Testing date
- Laboratory information
- Analytical methods
- Detection or quantification limits
The exact testing panel varies between products, laboratories and regulatory systems.
For example, UK government and FSA material demonstrates that cannabinoid analysis can involve methods such as HPLC and LC-MS/MS, while contaminant testing can involve methods including GC-MS/MS and ICP-MS.
For consumers, the key point is simple:
A COA should contain specific, traceable analytical information rather than simply saying “lab tested.”
Why Read a COA for Live Resin or Liquid Diamonds?
Live resin and liquid diamonds are terms used to describe different types of cannabis extract or formulations.
Your product name can tell you what the manufacturer calls the product, but a COA can provide analytical information about the actual tested sample.
For example, a report may help you understand:
- How much THC or THCA was detected
- Which minor cannabinoids were detected
- Whether terpene testing was performed
- Whether residual solvents were tested
- Whether pesticides were screened
- Whether heavy metals were tested
- Which batch was analysed
- When the sample was tested
- Which laboratory performed the analysis
This is one reason laboratory documentation can be more informative than relying on appearance, colour, texture or marketing language.
Our THC Concentrates Guide provides a broader explanation of live resin, live rosin, distillate, sauce, diamonds and other concentrate types.
Step 1: Check the Product Name
Start at the top of the COA.
Look for the sample name, product name or product description.
If the packaging says:
Live Resin Strawberry Gelato 1G
but the COA identifies the sample as something completely different, that deserves further investigation.
The product name should be reasonably consistent with the product you are evaluating.
However, minor naming differences do not automatically mean a report is fake. Brands and laboratories can use internal sample names or batch codes.
The important thing is whether you can establish a reasonable connection between:
Product → Batch → Laboratory report
Step 2: Find the Batch or Lot Number
The batch number is one of the most important pieces of information on a COA.
Look for terms such as:
- Batch No.
- Batch Number
- Lot No.
- Lot Number
- Sample ID
- Production Batch
- SKU
- Reference Number
Compare the number on the COA with the batch or lot information on the product packaging where available.
Why does the batch number matter?
Cannabis products can vary from batch to batch.
A COA for one batch does not automatically establish the composition of every other batch of the same product.
For example:
Product: Live Resin OG
Batch: LR-2401
and:
Product: Live Resin OG
Batch: LR-2402
may have different cannabinoid percentages or terpene profiles.
That is why batch-specific laboratory documentation is more informative than a generic laboratory report with no connection to the product.
Step 3: Check the Testing Date
Look for:
- Sample received date
- Testing date
- Report date
- Date of analysis
A COA should contain identifiable date information.
This allows you to understand when the laboratory tested the sample.
A very old report may not necessarily mean the product is automatically unsuitable, but it should prompt you to ask whether the report corresponds to the current batch.
Step 4: Identify the Laboratory
A legitimate-looking COA should identify the laboratory that performed the analysis.
Look for:
- Laboratory name
- Laboratory address
- Contact details
- Accreditation information where applicable
- Report number
- Testing methods
In the UK, ISO/IEC 17025 accreditation is particularly relevant to laboratory competence. The Home Office’s current cannabis/CBD/cannabinoid guidance discusses testing by suitably accredited laboratories and specifically identifies UKAS as the relevant UK accreditation body.
This does not mean that simply seeing an accreditation logo proves that every statement on a document is genuine.
Where possible, consumers should verify the laboratory and the report rather than relying solely on logos displayed on a PDF.
Step 5: Read the Cannabinoid Profile
The cannabinoid section is usually one of the most important parts of a cannabis COA.
You may see cannabinoids such as:
- Δ9-THC
- THCA
- CBD
- CBDA
- CBG
- CBGA
- CBN
- CBC
- THCV
- Other minor cannabinoids
The exact panel depends on the laboratory.
THC vs THCA
One of the most important distinctions is between THC and THCA.
THCA is the acidic precursor to THC. When heated, THCA can undergo decarboxylation and form THC.
Therefore, a COA may report:
THCA: 75%
and:
Δ9-THC: 2%
These are not the same measurement.
Do not automatically interpret a THCA percentage as equivalent to the measured Δ9-THC result.
This distinction becomes particularly important when reading reports for products marketed as THCA diamonds, liquid diamonds or diamond-infused formulations.
Our THC Diamonds Explained guide goes into greater detail about diamonds, THCA and laboratory testing.
Step 6: Understand Total THC
Some COAs provide a Total THC calculation.
This can involve measured THC plus a calculated contribution from THCA after decarboxylation.
The exact calculation and reporting convention can vary.
Therefore, don’t assume that:
THC + THCA = Total THC
without checking how the laboratory defines and calculates the result.
The reporting basis matters.
Some reports may show:
- % by weight
- mg/g
- mg per serving
- mg per container
- Total cannabinoids
- Total THC
These measurements are not interchangeable.
Step 7: Look at the Units
Pay attention to the unit beside each result.
You may see:
%
mg/g
mg/kg
ppm
or another unit.
For example:
1% = 10 mg/g
when both measurements refer to the same mass basis.
But a percentage cannot simply be compared with a result expressed per container unless you know the product weight.
This becomes especially important with disposable vapes and concentrates.
A 1G product and a 2G product may contain the same cannabinoid percentage while containing different total amounts of cannabinoids because their overall product weights differ.
Our THC Disposables Complete Guide explains the difference between product capacity and cannabinoid concentration.
Step 8: Check the Terpene Profile
Live resin is often associated with terpene-rich formulations.
If terpene testing is included, a COA may identify compounds such as:
- Myrcene
- Limonene
- Caryophyllene
- Linalool
- Humulene
- Pinene
- Terpinolene
The exact profile depends on the cannabis material and extraction process.
A terpene section can help you understand the reported chemical profile of the tested sample.
However, don’t assume that a terpene percentage automatically proves a product is “better.”
Terpene content is one characteristic of a product, not a universal quality score.
Step 9: Check for Residual Solvents
This section is particularly relevant when evaluating live resin or other solvent-extracted concentrates.
Depending on the extraction process, laboratories may test for residual solvents.
Potentially reported compounds can include:
- Ethanol
- Heptane
- Hexane
- Pentane
- Acetone
- Isopropyl alcohol
- Toluene
- Other solvents
The FSA’s testing work on cannabinoid products has demonstrated why residual-solvent testing can be relevant: its studies have included solvent analysis alongside cannabinoid, pesticide and heavy-metal testing.
A COA may report a result as:
ND
Not Detected
< LOQ
or with a numerical concentration.
What Does “ND” Mean on a COA?
ND generally means Not Detected under the conditions and reporting limits of that particular test.
It does not necessarily mean that absolutely zero molecules of the substance exist.
For example:
Residual Solvent: Hexane — ND
means the laboratory did not detect hexane at or above the applicable reporting threshold.
That is different from proving absolute absence.
What Does “<LOQ” Mean?
LOQ means Limit of Quantification.
If a COA says:
<LOQ
the laboratory is indicating that the substance was below the level at which it could reliably quantify the amount using that method.
This is an important distinction.
You should not automatically read:
<LOQ
as:
0.00
The actual reporting limit depends on the analytical method and laboratory.
Step 10: Look for Pesticide Testing
A comprehensive laboratory report may include pesticide screening.
The exact compounds and reporting thresholds depend on the testing programme and jurisdiction.
A pesticide panel may contain a long list of individual substances.
You might see results reported as:
ND
<LOQ
or a numerical concentration.
The FSA has conducted cannabinoid-product testing involving hundreds of pesticide compounds, illustrating why a meaningful pesticide panel can contain many individual analytes.
Don’t assume that a COA saying “pesticide tested” necessarily means every possible pesticide was tested.
Look at the actual panel.
Step 11: Check Heavy-Metal Testing
Heavy-metal testing may include:
- Lead
- Arsenic
- Cadmium
- Mercury
Advanced laboratory methods can measure these contaminants at very low concentrations.
For example, FSA materials show the use of ICP-MS methods for elemental impurities such as arsenic, cadmium, lead and mercury.
Again, look for the actual results rather than relying on a headline statement such as:
“Heavy Metal Tested.”
Step 12: Look for Microbial Testing
Depending on the product and applicable testing requirements, a COA may include microbiological analysis.
Possible categories can include:
- Yeast
- Mold
- Bacteria
- Other microbial contaminants
Not every COA will contain identical testing categories.
The important question is:
What exactly did this laboratory test for?
How to Read a Liquid Diamonds COA
The term “liquid diamonds” is not a single standardized analytical category.
Depending on the product, it may refer to a formulation involving cannabinoid crystals, distillate, terpene-rich material or other components.
Therefore, the COA is particularly useful.
Instead of judging the product by the words “liquid diamonds,” look at:
Cannabinoids
Check:
- Δ9-THC
- THCA
- Minor cannabinoids
- Total cannabinoid content
Terpenes
Check whether terpene testing was performed and which compounds were reported.
Residual solvents
Check whether the relevant solvent panel was tested and what the results show.
Contaminants
Check:
- Pesticides
- Heavy metals
- Microbial contaminants
Product identity
Check:
- Product name
- Batch number
- Sample ID
- Test date
- Laboratory
The terminology used on the front of the package is less useful if the underlying laboratory documentation cannot be connected to the actual batch.
Live Resin COA vs Liquid Diamonds COA
The process of reading the two reports is broadly similar.
| COA section | Live Resin | Liquid Diamonds |
|---|---|---|
| Product identity | Check | Check |
| Batch number | Check | Check |
| THC | Check | Check |
| THCA | Check | Check |
| Minor cannabinoids | Useful | Useful |
| Terpenes | Particularly useful | Useful |
| Residual solvents | Important where applicable | Important where applicable |
| Pesticides | Check | Check |
| Heavy metals | Check | Check |
| Microbial testing | Where applicable | Where applicable |
| Laboratory details | Check | Check |
The main difference is that you should pay particular attention to THCA, THC, formulation and terpene informationwhen evaluating products marketed around diamonds.
Red Flags When Reading a COA
A COA should encourage questions rather than automatically create confidence.
Watch for:
1. No batch number
If the product has a batch number but the COA doesn’t identify one, ask how the report relates to the product.
2. Product name doesn’t match
A significant mismatch between the product and laboratory sample should be investigated.
3. No laboratory identification
A report with no identifiable testing laboratory provides limited verification.
4. Potency only
A document showing only THC percentage is not the same thing as a comprehensive testing panel.
5. Missing test dates
A report without clear date information makes it harder to establish when the sample was analysed.
6. No analytical methods
A detailed laboratory report normally provides information about the methods used.
7. Suspiciously generic results
If every contaminant simply says “PASS” without identifying what was tested or the reporting limits, there is less information available for independent evaluation.
8. QR code that goes nowhere useful
A QR code is only useful if it leads to meaningful documentation that can be connected to the product.
9. COA doesn’t match the package
This is one of the most important checks.
The report should correspond to the product and batch where applicable.
Does a COA Prove a THC Product Is Legal in the UK?
No.
This distinction is extremely important.
A COA tells you about laboratory analysis.
It does not automatically establish:
- Legal status
- Licensing status
- Whether the product can legally be sold
- Whether possession is lawful
- Whether importation is lawful
- Whether advertising is lawful
UK controlled-drug rules are separate from laboratory testing.
The Home Office’s current guidance discusses testing requirements in relation to demonstrating compliance, including appropriately sensitive analysis by suitably accredited laboratories.
For the broader legal position, see our UK Cannabis Laws: A 2026 Guide.
How to Verify a COA Before Buying a Cannabis Product
A useful five-step process is:
1. Find the COA
Look for the laboratory report associated with the product.
2. Match the product
Compare the product name, SKU and description.
3. Match the batch
Compare the batch or lot number.
4. Check the laboratory
Identify the laboratory and review its stated accreditation and analytical capabilities where applicable.
5. Read the actual results
Don’t stop at the phrase:
“Lab Tested.”
Review the cannabinoid, terpene and contaminant sections.
This approach gives you considerably more information than simply judging a product from its packaging.
COA Checklist for Live Resin and Liquid Diamonds
Before evaluating a live resin or liquid diamonds product, work through this checklist:
Product identification
- Product name matches
- Batch number matches
- Sample ID is provided
- Test date is provided
Laboratory
- Laboratory is identified
- Report number is provided
- Analytical methods are stated
- Accreditation information is available where relevant
Cannabinoids
- Δ9-THC reported
- THCA reported where relevant
- Minor cannabinoids identified where applicable
- Units are clearly stated
Terpenes
- Terpene testing identified where applicable
- Individual terpene results are provided
Contaminants
- Residual solvents
- Pesticides
- Heavy metals
- Microbial testing where applicable
Verification
- COA corresponds to the actual product
- Batch information can be cross-checked
- Results are presented rather than just “PASS”
- Legal status is assessed separately from laboratory results
COA vs Product Label: What’s the Difference?
The product label tells you what the manufacturer says is in the product.
The COA provides laboratory results for a tested sample.
Ideally, the two should be reasonably consistent.
For example:
Label: Live Resin — 1G
COA: Live Resin — 1G
Batch: LR-2026-08
COA Batch: LR-2026-08
That gives you a traceable connection between the product and the laboratory report.
If the label and COA appear unrelated, further verification is appropriate.
Why COAs Matter When Comparing Live Resin Products
Two products can both be marketed as live resin while differing substantially in:
- Cannabinoid profile
- Terpene profile
- Extraction method
- Starting material
- Hardware
- Testing
- Batch results
That is why the phrase “live resin” alone doesn’t tell you everything about the product.
Our Live Resin and Concentrates Guide explains the differences between live resin, live rosin, distillate and other concentrate categories.
For vape products specifically, our THC Vape UK Guide covers extract types, cannabinoids, terpenes, product quality and safety considerations.
Final Takeaway: How to Read a Live Resin or Liquid Diamonds COA
A COA is most useful when you know what you are looking at.
Start with the product name, batch number, sample ID, testing date and laboratory. Then move through the cannabinoid profile, THC and THCA measurements, terpene results and contaminant panels.
Pay particular attention to:
THC vs THCA
% vs mg/g
ND vs <LOQ
Batch-specific testing
Residual solvents
Pesticides
Heavy metals
Laboratory identity and methodology
Most importantly, don’t confuse a laboratory report with a legal certification.
For UK consumers, the legal status of a cannabis or cannabinoid product must be assessed separately under the applicable legislation.
A good COA gives you more information to evaluate a product. It does not replace checking the product’s source, formulation, applicable regulations or legal status.
For further reading, explore our THC Concentrates Guide, THC Diamonds Explained, THC Disposables Complete Guideand UK Cannabis Laws Guide.