Before the percentage, look for identification
Start with the laboratory, report number, sample identification and declared batch. Then check the dates: receipt, analysis and issue may be different. This information connects the document to a particular material. If the packaging and report cannot be linked, a very precise figure may be answering the wrong question.
New Jersey’s regulator provides a public guide to reading certificates that distinguishes identification from results. It is an educational reference from another jurisdiction, not the rule that applies in Spain. It helps show how a document organises information before its tables are interpreted. New Jersey: how to read a certificate of analysis
A fictional example, just for learning
Suppose a fictional document says: “Sample MN-EXAMPLE-01; batch TEACHING-A; matrix: oil-based preparation; received: 10 October; analysed: 12 October.” It does not correspond to any real product or represent validation by Milnubes. If your imaginary packaging says TEACHING-B, there is already a discrepancy to resolve before discussing percentages.
Now we add “CBD: 25 mg/g” and “analyte X: below the stated limit of quantification”. The first figure expresses mass per mass, not milligrams in the whole bottle. The second does not mean zero. If the report includes another table for metals or microbiology, each section needs its own reading; the absence of that section cannot be turned into a favourable result.
What was looked for, and how it is expressed
The panel of analytes defines the scope of the search. A cannabinoid profile is not a pesticide analysis. Units indicate how the result is expressed; the matrix identifies the type of material. Comparing a cream with a powder requires methods suitable for each composition, not simply that both bear the word hemp.
Health Canada explains in its validation guidance that methods must demonstrate appropriate performance and that matrices can affect measurement. The Canadian example helps explain an analytical principle: a method is not assessed solely by the name of its instrument. Its performance for the intended measurement matters. Health Canada: validating analytical methods
Limits and uncertainty are not faults in a report
Detection and quantification limits describe the capabilities of the method. Uncertainty expresses part of what we know about the measurement. Including these does not weaken a document; hiding them does not make a figure more accurate either. When a result is close to a decision criterion, interpretation particularly requires understanding how that criterion is applied.
In the fictional example, writing 25.0000 mg/g would not magically make a measurement more reliable than 25 mg/g through formatting. Decimal places should reflect the laboratory’s reporting approach. A table’s design can convey great confidence, but visual precision and metrological quality are not the same thing.
A stamp has a scope
If accreditation is claimed, check the body and the applicable scope. A laboratory’s accreditation does not necessarily mean that every test it offers is covered. ENAC explains the role of accreditation standards and the activities assessed. This detail takes you from a logo to a specific check. ENAC: accreditation standards and process
It is also worth looking for complete pages, notes and any corrected versions. A cropped screenshot can omit a result’s context. If authenticity is in doubt, the useful approach is to confirm the report with its issuer using verifiable details. A QR code makes a document easier to reach, but its presence does not itself prove that the document is correct.
The conclusion must stay within the document
A certificate can support a statement about composition within its scope. By itself, it does not demonstrate clinical efficacy, the legality of every use, the quality of all batches or the absence of every imaginable contaminant. Each question requires additional information. Careful reading preserves these boundaries without diminishing the value of the analysis.
A good review ends with a precise statement: “this report corresponds to this sample and provides these results”. It sounds less impressive than “guaranteed product”, but allows better-informed decisions. It also gives you a clear path for further reading: batches, units, limits, contaminants and accreditation are chapters of the same story, not decorations in a table.
Take this with you
A useful COA connects sample, batch, method and result. Its scope is valuable precisely because its boundaries can be defined.
Sources you can open
The source may be in its original language. English publication does not change the jurisdiction or date discussed.
Follow the thread
Open the cannabinoid encyclopedia
Check the identity, research, uncertainties and documented forms of each compound.