Factory certificates of analysis often report against the factory’s own house specification, which is not the specification you buy against (the document your own incoming quality checks use). The two usually differ in small ways, and the difference is normally discovered at your warehouse, or in the mud, not while the documents are being checked. Below: the checking built into a chemical order, and the lot-report format it produces.
Four steps. First, we capture the specification your own quality checks use, and it becomes part of the order. A factory sales sheet is not that document. Second, we match the order to a factory we vet: its export record, and its product against the data we require from it. Third, before shipment we require the factory’s laboratory test report for your production lot, reported against the specification you ordered, and we send it to you before the container ships. Fourth, you may appoint an independent inspector (SGS, Bureau Veritas, or your own choice) to sample, test and witness loading; you pay the inspection fee.
Any supplier’s material is tested in the factory’s own laboratory, and the quality of that testing varies. Ironstone does not operate a laboratory, and we do not claim to re-test material ourselves.What we change is what the report is tested against and who sees it: many factory certificates report against the factory’s own house specification rather than the specification you ordered. We require the report for your lot against the specification you ordered, we check the two documents line by line, and we send you the report before shipment, so any difference is found while the goods are still at the factory, before they reach your warehouse. Where you want testing that is independent of the factory, you appoint the inspector and the inspector reports to you.
The report is a table with one row per parameter of your specification: the limit you ordered, the tested result for your production lot, the test method, and whether the row passes. The example below shows the format for a low-viscosity polyanionic cellulose (PAC-LV) ordered against a buyer’s own specification.
| Parameter | Your specification | Lot result | Method | Pass |
|---|---|---|---|---|
| Lot number | — | SPECIMEN — no order | Printed on report and bags | — |
| Appearance | Free-flowing powder, off-white to cream | Conforms | Visual | Yes |
| Active polymer content, dry basis | ≥ 80% | 84.2% | Ethanol-wash gravimetric, per the order | Yes |
| Moisture | ≤ 10% | 7.6% | Oven drying | Yes |
| Apparent viscosity | Per your specification | Reported per lot | API Spec 13A method where quoted to 13A | — |
| API filtrate | Per your specification | Reported per lot | API Spec 13A method where quoted to 13A | — |
| pH, 1% solution | 6.0–8.5 | 7.1 | pH meter | Yes |
The test method column matters: a result without its method cannot be compared with your own laboratory’s result. The report also carries the production lot number, printed on the bags as well, so any delivery can be traced back to this document.
If the factory’s lot report fails your specification before shipment, the lot does not ship. It is reworked or replaced before the remaining payment is due. If material that shipped does not meet the specification we agreed, we replace it or refund it, and that commitment is written on the quotation. What we ask from you is the evidence the commitment depends on: keep a sealed retained sample from the delivery, and raise the claim against the lot number on the report.
This is a checking system built on documents and inspection, not a laboratory. It targets a common documentary failure — material tested against the wrong specification — and the independent-inspector route exists for what a document check cannot catch. It does not replace your incoming quality checks, and we do not ask you to skip them.