How to verify a Certificate of Analysis (COA)
A five-minute checklist to confirm the COA matches your container and your specification - before you open or use the material.
A COA only protects you if you check it against the pack. Use this list on every delivery.
Verification checklist
- Batch / lot number on the COA equals the number on the container label.
- Product name, grade, and CAS match the purchase order.
- Every result is within the stated specification limit.
- Retest / expiry date is still valid for your use window.
- Document is signed / stamped by QC (or carries a clear electronic authentication).
Red flags
- Generic “typical values” with no batch number.
- COA date far older than the manufacturing date on the pack.
- Assay or impurity results outside limits with no deviation note.
Full field-by-field guide: how to read a COA. Lubechem ships a batch-specific COA with every order - request one before purchase via contact.
Frequently asked questions
What if the batch number on the COA does not match the pack?
Do not use the material. Quarantine it and contact the supplier immediately with photos of the label and COA.
Is a PDF COA acceptable for audits?
Usually yes if it is batch-specific and traceable. Regulated buyers may also request hard copy or portal access - ask your QA team.
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