A Certificate of Analysis (COA) is one of the most important documents in a charcoal purchase - but only if you know how to read it. In this guide, we explain the standard parameters, how to compare a COA against a commercial specification, and the questions to ask your supplier.
What a COA Contains
A typical COA for coconut shell charcoal briquettes records the measured values of a tested batch for a set of defined parameters:
- Moisture content: The water content of the briquettes at testing
- Ash content: The non-combustible residue remaining after combustion
- Volatile matter: Components released when the material is heated
- Fixed carbon: Calculated from moisture, ash, and volatile matter
- Calorific value: The energy content per kilogram
- Ash colour: The observed colour of the ash after combustion
COA vs Commercial Specification
The COA records the results of a specific sample. The commercial specification defines the agreed ranges for each quality grade.
For example, the three grades offered by Charcoalnesia - Platinum, Super Premium, and Premium - define agreed ranges for ash content, moisture, and volatile matter, plus targets for fixed carbon and calorific value. The COA of your batch should be read against the agreed range of the grade you ordered - not against a different grade or a generic marketing claim.
How to Compare COAs
When comparing COAs from different suppliers, check:
1. Which parameters were tested, and by which laboratory 2. Whether the results fall within the agreed specification ranges 3. The sample date and the relation to your production batch 4. Whether the COA covers the grade, dimensions, and packaging you ordered
Questions to Ask Your Supplier
- Which parameters are included in the applicable COA for this product and grade?
- Are results batch-specific, and which batch do they refer to?
- Is third-party testing available when required by contract or destination?
Conclusion
A COA is useful when it is read against the agreed specification. Confirm the grade, the parameter ranges, and the documents that apply to your order and shipment before committing volume - and request an evaluation sample to verify performance.