Certificate of analysis: reading one instead of filing it

A certificate of analysis is the supplier’s statement of what they tested on a specific batch and what the results were. It arrives with the delivery, it is usually filed within seconds of being received, and it is often the only technical evidence you hold about material that goes into your product. The two-minute read at goods-in is what separates a document that protects you from one that merely exists.

What a certificate of analysis has to show

• The batch or lot number, matching the material physically in front of you rather than the order.
• The product identity and grade exactly as you specified it, not a near neighbour.
• Each test performed, the method used, the specification limit and the actual result — a result with no limit beside it is not verifiable.
• The date of manufacture and, where it applies, the retest or expiry date.
• Who authorised the release, by name or role.
• Whether the results are from testing this batch or carried over from a previous one, which is a real and legitimate practice that must be disclosed.

The checks that take a minute

1. Does the batch number on the certificate match the batch number on the container? This single check catches more errors than every other combined.
2. Are all your specified parameters present, or only the supplier’s standard set? A missing parameter is the most common quiet substitution.
3. Does every result sit inside the limit — and where a result is exactly at the limit, is that plausible or suspiciously convenient?
4. Is the method stated, and is it the method you agreed? The same parameter measured two ways can give two different answers.
5. Is the certificate for the material you actually received, or a generic type certificate for the product line?

A certificate of analysis is a supplier’s claim, not an independent verification. Where the material is critical, periodic identity or full testing on receipt is what turns the claim into evidence — and the frequency of that testing should be a written decision based on risk and supplier history, not on how busy the lab is that week.

Keeping them so they can be found

• One certificate per received batch, linked to the goods received note rather than filed by supplier and date.
• Traceable forward: which of your batches used which incoming lot, so a supplier recall becomes a query rather than a week of paper.
• Retained at least as long as the product it went into plus its shelf life, which is usually longer than your purchasing records are kept.
• Deviations from specification recorded as a decision — accepted under concession, rejected, or returned — never as an unremarked file.
• Where the batch record depends on these values, take them from the certificate once rather than retyping them in two places.

Where a part is new or its process has changed, the certificates and measurements come together in a first article inspection report, which proves the production process — not just one sample — can make the part to drawing.

Where the certificates live

Ettex Records holds each certificate against the batch it describes, with the supplier, the lot, the receipt date and the acceptance decision as fields, so a recall notice from a supplier turns into a filter rather than an archaeology exercise. It sits next to the goods received note and the batch record, which is where the forward and backward traceability actually joins up. Ettex does not test materials, does not verify supplier claims and does not issue certificates — it keeps the ones you receive findable and tied to what you did with the material.