A certificate of analysis, or COA, is an independent laboratory report on a specific batch of product. It is the difference between a brand telling you what is in a bottle and a third party confirming it.

Batch-specific, not product-specific

This is the detail most people miss. A COA covers one batch, not a product line in general. Ingredients and extraction runs vary, which is exactly why batch testing exists.

So when you check a report, match the batch number on your packaging to the batch number on the document. A COA for a different batch tells you about a different batch.

What the report shows

Cannabinoid profile

The core of the document. It lists the cannabinoids detected and their concentrations — CBD, THC, and typically minor cannabinoids such as CBG, CBC and CBN. Compare the CBD figure here against what the label claims.

You may see two columns: results for the raw extract and for the finished product. The finished-product figures are the relevant ones.

THC content

Reported either as a percentage or in mg. On a broad spectrum or isolate product you would expect this to read as non-detect, often shown as “ND” or below the lab’s limit of quantification.

Safety screening

A thorough COA goes beyond cannabinoids. Depending on scope it may cover:

• Heavy metals — hemp draws metals up from soil, so this one matters
• Pesticides
• Residual solvents left over from extraction
• Microbials — bacteria, yeast and mould

Each is normally reported as pass/fail against a defined limit.

Reading it critically

A few things worth checking on any COA:

• Who issued it. An independent, accredited laboratory carries more weight than an in-house result.
• The date. Reports should be reasonably recent relative to the batch.
• Whether the batch matches. As above — this is the one to verify first.
• Whether claims line up. If the label says 1000mg and the report says materially less, that gap is the story.
• What is not tested. A cannabinoid-only report is not a full safety screen.

“Available on request” is a reasonable answer

Not every brand publishes every report openly, and asking for one is a normal thing to do. What matters is whether you get a clear answer. A supplier who cannot produce a report for the batch you bought has told you something useful.

Our reports

CBDBLOOM batch documentation is published on our lab reports page. If the batch you are looking for is not listed, email sales@cbdbloom.co.uk with the batch number printed on your packaging and we will send it over.

Important: This article explains laboratory documentation and is not medical advice. CBD products are food supplements and are not intended to diagnose, treat, cure or prevent any disease.