CoA · Batch QC

Certificate of analysis template

Fill the product header, batch identifiers, and one row per test parameter. The tool generates a one-page Certificate of Analysis PDF in the Sourzi format. Sign and stamp; ship with the cargo.

Last updated 2026-05-08. Math runs in your browser, no data leaves your computer.

General guidance only, not legal or professional engineering advice. Verify against the cited primary sources (IMDG, REACH, ChAFTA, RCEP, Customs Tariff Act, supplier SDS, etc.) before committing to a shipment, declaration, or contract. Sourzi assumes no liability for outcomes based on these calculators.

A CoA is per batch. Match the batch number to the marks-and-numbers on the cargo and the bill of lading; that is what makes the document useful in a downstream recall event.

Product

Batch identifiers

Test parameters

One row per assay. Method should reference the relevant standard (USP, BP, FCC, ASTM, ISO). Specification is the agreed range or limit; result is the actual test outcome.

Issuer

Why the CoA is the QC handshake

Quality control is two parties testing the same cargo against the same spec. The seller QC lab tests the production batch and issues the CoA; the buyer QC lab tests the received cargo and verifies the CoA against the actual sample. When the two sets of results agree, QC passes; when they disagree, the dispute starts. The CoA is the document the buyer side uses to anchor the comparison; without it, the buyer is testing into the dark.

The test parameter rows are the body of the document. Purity is the headline number for most chemical cargo. Water content, heavy metals, residual solvents, particle size, and density are the secondary parameters depending on the product. For each parameter, the CoA needs four cells: the parameter name, the test method (USP, BP, FCC, ASTM, ISO), the specification (the agreed range or limit), and the actual result. Methods matter because two methods can give different results on the same cargo; "purity by HPLC" and "purity by titration" are not interchangeable for citric acid even though both report a percentage.

Specification ranges should match the PO. If the PO says "purity 99.5 percent minimum", the CoA spec column should say "≥ 99.5%" and the result column should report the actual measured purity. If the spec column on the CoA says "99 percent minimum" while the PO said 99.5 percent, the document is internally inconsistent and the buyer side will flag it. Keep the spec wording identical between PO, CoA, and the SDS.

The signature line is the QC manager personal accountability for the document. Some Chinese factories add the company chop (公章); the chop is an institutional commitment in addition to the personal signature. Either is acceptable; both is stronger. A CoA without a signature or chop is paper, not a commitment.

Worked example. The retest miss

The booking. A US food-and-beverage manufacturer receives a 25,000 kg shipment of citric acid monohydrate from a Shanghai supplier. The CoA accompanies the cargo: batch B26050801, manufactured 1 May 2026, retest date 1 May 2028, FCC grade per USP-NF, purity 99.7 percent (spec 99.5 percent minimum), heavy metals 1.2 ppm (spec ≤2 ppm), water content 7.8 percent (spec 7 to 9 percent). Buyer QC pulls a sample on receipt and runs the assay panel. Looks fine on paper.

The failure. Buyer QC purity test returns 99.4 percent, 0.1 percentage point below spec. Buyer rejects the cargo on the basis of the failed retest. Supplier insists their CoA at production was 99.7 percent. Both numbers are honest. The 19 days between manufacture and buyer receipt include 21 to 35 days of ocean transit at varying humidity (the cargo passed through the Red Sea at 35 to 38 degrees Celsius); citric acid monohydrate is hygroscopic, water content rose, the apparent purity dropped accordingly. Neither side is wrong; the CoA is correct as of the manufacture date but does not reflect the cargo at receipt.

The fix. On the next shipment, the buyer asks the supplier to set the spec column on the CoA to "Purity by HPLC ≥ 99.3% on receipt at buyer warehouse, ≥ 99.5% as manufactured". The CoA reports the as-manufactured number; the buyer accepts retest down to 99.3 percent on the basis that hygroscopic loss in transit is a known and unavoidable phenomenon. Both sides have a clear acceptance criterion. The cargo passes the next 8 shipments. The CoA still serves the QC handshake; the spec is now realistic against the transit conditions.

Frequently asked

What is a Certificate of Analysis (CoA)?

A CoA is the document the manufacturer (or the QC laboratory the manufacturer uses) issues for each production batch, showing the test results against the agreed specification. It accompanies the cargo through customs, lands in the buyer QC inbox, and is the document referenced if a downstream batch fails. A CoA per batch is the standard for chemical procurement; some buyers require a CoA per batch plus a CoA per shipment if the shipment is split across multiple production batches.

What goes on a CoA?

Eight fields: product name and grade; CAS number; batch number; manufacture date; expiry or retest date; test parameters (one row per assay) with method (USP, BP, FCC, ASTM, ISO), specification, and result; the QC manager signature and date; the seller company stamp. The CoA is read by the buyer QC team alongside the SDS and the spec sheet.

Should the CoA come from the factory QC lab or a third-party lab?

For commodity chemicals, factory QC is the norm and is acceptable to most buyers. For pharmaceutical-grade, food-grade (FCC), or fine chemical grades where the buyer downstream has audit obligations, a third-party CoA from SGS or Bureau Veritas (or the buyer named lab) is sometimes contractually required. Reference the requirement in the PO and the commercial invoice; do not assume the factory CoA will be accepted at the buyer side.

Why does the CoA need a batch number that matches the cargo?

Batch traceability. If a batch fails QC at the buyer customer (for example a food-and-beverage contamination event), the buyer needs to recall every shipment that came from the same factory production batch. The batch number on the CoA, the marks-and-numbers on the cargo, the BL, and the commercial invoice should all reference the same batch identifier so the recall scope is unambiguous. A CoA without a batch number is not useful in a contamination event.

How long should a CoA be retained?

Typically 3 to 5 years past the cargo expiry date, longer for pharmaceutical and food-grade chemicals where the buyer downstream may have a 7 to 10 year audit retention requirement. The seller side retains the original; the buyer side retains a copy. Both sides need the document available if a regulator queries the cargo years later.

Can a CoA be issued before the batch is fully tested?

No. The CoA reports actual test results, not predicted results. Issuing a CoA before all parameters are tested is paper that does not reflect reality, and a downstream failure surfaces it as the source. Wait for the QC lab to complete the assay panel; release the CoA when the data is in.

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