Spec sheet vs COA

By Mohamad Sinno, Charcoal Expert · published 7 September 2026. Not reviewed by the Head of QC — the reviewer byline on our older quality pages carries the date those pages were read, and this one has not been read yet.

A specification describes what a product is supposed to be, in general. A certificate of analysis reports what a laboratory measured, on one sample, from one batch. Buyers are routinely sent the first and told it is the second, and the swap is easy to miss because both documents are a table of the same parameter names.

The short answer

One reference guide puts the distinction cleanly: a specification sheet describes the general, expected properties across all lots, while a certificate of analysis reports the actual test results measured for one specific lot against that specification (casrai.org, reference guide, published 12 August 2026). Everything else follows from that sentence. A specification is a promise about a product line. A certificate is evidence about a consignment.

The practical consequence is that a specification cannot be out of date and a certificate can. It also means a specification is never wrong about your shipment — it simply is not about your shipment at all.

Document, proof, and when to demand it

The red flag: "Typical" in the results column

A certificate has two columns that matter. The specification column states the limit; the result column states what this batch did. When the result column says "Typical", or "Conforms", or repeats the specification back at you, the document has quietly become a datasheet with a certificate's title. One chemical supplier's guide names that as the commonest red flag it sees (alliancechemical.com, chemical supplier, 4 November 2025).

The second thing to check is not on the document at all. The lot number on the certificate has to be the lot number on the goods — described in the same reference guide as the single most common verification failure found in supplier audits, and echoed by a chemical retailer's guidance that checking the document but not the batch number is how buyers accept an undocumented consignment while believing they verified it (chemazon.store, chemical retailer, updated 23 July 2026). Two batches of the same grade from the same supplier can carry visibly different numbers, and that is normal — which is exactly why the batch has to be identified.

What we publish instead of a spec sheet

This site does not publish a table of typical values, because we do not have one that means anything. What exists is three lab reports from one named laboratory, and the honest way to present three measurements is as a range with the count attached:

Three samples are three samples. That range is not a specification, a guarantee, or a prediction about the next batch — it is the spread three certificates happened to record, and the reason it is published as a spread is that flattening it to one number would be inventing a spec sheet after all. None of the three states whether its figures are as-received or dry, so no basis is claimed here either.

Your document checklist

1. At quotation: the specification, so the parameters are agreed before anything is priced.
2. Before the deposit: the figures written into the contract with an acceptance window and a remedy. Ours are a claims window of seven days from receipt, with replacement or credit as the remedy.
3. With every sample: a batch COA. Samples without one tell you about appearance and nothing else.
4. Per shipment: the certificate for the batch you are receiving, with its number and dates, verifiable at the laboratory — how to check that it is real.
5. On arrival: the batch code on the cartons matched back to the paperwork. The mechanics are in the audit protocol.

Transport and customs paperwork is a separate stack with its own failure modes — that lives with the import documentation guides.

Common questions

What is the difference between a spec sheet and a COA?

A spec sheet states what a product is supposed to be; a certificate of analysis states what one tested sample actually measured, with a date, a method and a report number. The first is a promise written by the seller, the second is evidence written by a laboratory. Only one of them can be checked against the goods you received.

Why do you not publish a typical-values spec sheet?

Because the honest version of it is the measured range from the certificates we hold, and we publish that instead. A typical-values table is a set of numbers with nothing behind them; once you have three numbered reports, printing a rounder, friendlier set of figures beside them adds nothing except the option of quoting the friendlier ones.

The results column on a COA says "Typical". Is that normal?

No. The results column records what was measured on the sample. "Typical", "approx." or a range in that column means the document is a specification wearing a certificate’s layout, and it should be sent back with a request for the measured values and the method used to get them.

Which document do I put in the contract?

The specification defines the ceiling you are buying to, and the COA proves each shipment against it — so the contract names the ceiling and requires a batch certificate for every consignment. A contract that references only a spec sheet has no evidence mechanism, and one that references only a certificate has nothing to measure the next batch against.