What a COA is
A certificate of analysis, or COA, is a lab report for one specific batch of product. It lists each test, the method used, the specification limit and the result. It can come from the producer's own lab or from an independent lab, and it should carry a batch number that matches your shipment.
Typical parameters for psyllium husk
| Parameter | What it tells you |
|---|---|
| Appearance and color | Whether the husk looks like the grade you ordered |
| Purity (% husk) | The share of pure husk. The rest is seed fragments and other matter |
| Particle size or mesh | Whole husk or powder, and how fine it is |
| Moisture | Too much moisture shortens shelf life and raises the risk of mold |
| Total ash and acid-insoluble ash | Mineral content, and whether sand or soil is present |
| Swell volume (ml/g) | How much the husk swells in water, a key functional measure |
| Foreign matter | Visible contamination |
| Microbiology | Total plate count, yeast and mold, E. coli and Salmonella |
| Heavy metals | Lead, arsenic, cadmium and mercury |
| Pesticide residues | Whether residues are within the limits of your market |
The exact list depends on your specification and your destination. Ask for the parameters you need in writing before you order.
How to read one
- The batch or lot number matches the product you are buying.
- The test date is recent.
- Each result is shown next to a specification limit, so you can see whether it passes.
- The test method is named for each parameter.
- The lab is named, ideally an accredited one, for example to ISO/IEC 17025.
- The limits meet your specification, not only the supplier's own.
Red flags
- No batch number, test date or lab name.
- Identical results on every batch, to the last decimal place.
- Parameters you asked for are missing.
- No test methods listed.
- Results that cannot be matched to the product you receive. A COA is only useful if you can trace it to the lot.
Compare the supplier's COA with a test on your own incoming sample. The two should agree closely, and if they do not, ask why before you place a larger order.
Ask for a COA before you order
Samples and a Certificate of Analysis are available on request. Send your grade, quantity and destination through the enquiry form and we will arrange them.