Spotting test certificates that were never really tested

A certificate of analysis is easy to produce and hard to verify, which makes it the most commonly abused document in chemical trade. Most forgeries are not clever. They are templates with a new batch number typed in.

Start with internal consistency

Check the obvious things first, because most weak certificates fail here.

• The batch number on the COA should match the batch number on the label, the packing list and the shipping documents
• The test methods named should be methods that make sense for the parameter, not generic entries
• The results should vary between batches; identical values across a year of production are a signature
• The issue date should precede the shipment date, and the signature should belong to a named person
• The specification column should match the TDS, including units and basis

Look at the laboratory, not the letterhead

A real third-party report names the laboratory, the report number and usually an accreditation mark with a number you can check. Call or look up the laboratory independently rather than using contact details printed on the certificate itself.

In-house certificates are normal and acceptable. What you want in that case is evidence that the in-house lab exists: instrument list with calibration dates, a sample of raw data, or the lab visible in an audit.

Verify one result independently, once

You do not need to retest everything. Pick the parameter that matters most to your process and have a sample tested at a laboratory you selected. If the independent result lands within the stated specification, you have evidence the supplier's numbers are in the right range. If it does not, you have a much larger problem than one document.

This single test changes the incentive. Suppliers who know a buyer occasionally verifies are less likely to circulate templates.

Red flags worth acting on

• A PDF that is a scan of a scan, with no metadata and a logo that does not match the supplier's other documents
• Results reported to more decimal places than the stated method can support
• A certificate covering several different products with one batch number
• A laboratory nobody can find, with no accreditation number
• A supplier who sends a certificate but will not send the batch label photo

What to do in the contract

Name the test method and the acceptance criteria, and state what happens if an independent test disagrees. Specify that a retention sample is kept by both sides for an agreed period. Those two clauses do more than any amount of document checking, because they define the consequence.