Certificate of conformance vs certificate of analysis vs spec sheet: what each document proves

Five documents that get confused

Suppliers send several documents with a product, and the names are used loosely. The distinction matters because only one of them reports what was measured on the material you received. This guide takes each definition from a primary source: ICH Q7 for certificates of analysis and specifications, the US Federal Acquisition Regulation for certificates of conformance, OSHA for safety data sheets and GOV.UK for proof of origin. [1] [2] [3] [4] [5]

What each document is

Certificate of analysis (COA). ICH Q7 expects an authentic COA for each batch on request, giving the product name, grade, batch number and release date, each test performed with its acceptance limits and numerical results, and the expiry or retest date where applicable. It should be dated and signed by authorised quality-unit staff and name the original manufacturer. [1]

Specification. Q7 defines it as a list of tests, references to analytical procedures and acceptance criteria to which material should conform. [1] A specification or technical data sheet describes what any lot should meet; it reports nothing about a particular lot.

Certificate of conformance (CoC). In US federal purchasing, the contractor signs a certificate that the supplies meet all applicable requirements, are of the quality specified and conform in all respects with the contract, in the quantity shown. [3] The FAR allows acceptance on a CoC when small losses would follow a defect or the contractor's record makes acceptable supplies likely, and the buyer keeps its right to inspect. [2] A CoC is an assurance backed by the signer's accountability, not a test report.

Safety data sheet (SDS). OSHA requires manufacturers and importers to prepare labels and safety data sheets that convey hazard information downstream, in a 16-section format. [4] It is a hazard document for the product, not evidence of a lot's identity or purity.

Statement or certificate of origin. Proof that lets an importer claim reduced or nil duty under a trade agreement. GOV.UK describes an origin declaration, also called a statement on origin, placed on a commercial document such as an invoice, packing list or delivery note; some agreements instead let the importer rely on its own knowledge, backed by records. [5]

Side by side

Use this to decide which document answers the question you have.

How one document gets substituted for another

A specification presented as a COA: the document lists purity and identity limits but no batch number, no date and no results. It shows what the supplier aims for, not what it measured.

A CoC in place of a COA: a signed statement that the product meets specification, without data. It may be acceptable when a defect would cost little and the supplier has a track record, which is the FAR's own test, but it does not let you check anything yourself. [2]

A distributor's re-issued COA: Q7 says certificates re-issued by repackers, agents or brokers should name the laboratory that did the analysis and the original manufacturer, and attach a copy of the original certificate. [1] A re-typed COA with no laboratory name loses that chain.

A sample or library certificate: a report for a different batch posted on a website. It shows the supplier tests something; it does not show your lot was tested.

What three suppliers published on 30 October 2026

OMNI Peptides' site links a COA library advertised as batch-specific, but its terms say certificates of analysis are provided for informational purposes only and that it does not warrant the accuracy of information on the site. [6] Evolve Peptides' lookup asks for the batch number on your label and returns that batch's certificate and endotoxin report; it says reports come from independent labs without naming them. [7] Peptides EU's FAQ says selected independent certificates from Janoshik Analytical are published, describes certificates as optional for each product, and does not say what ships with an order. [8] None of the pages we read mentioned a certificate of conformance or an SDS.

What to ask for instead

If you receive anything other than a lot-specific COA, ask for one in these terms. The site's guide to requesting a COA has a full template.

• A certificate of analysis for lot [number on the vial], dated and signed, listing each test, method, acceptance limit and numerical result.
• The name and address of the laboratory that performed each test, and of the original manufacturer if you bought from a distributor.
• The original manufacturer's certificate, attached, if the one you received was re-issued.
• The SDS separately, as a hazard document, not as quality evidence.
• A statement on origin on the invoice if you import and want to claim a duty preference.