ALFAISAL INSIGHTS ·
Technical Data Sheet vs Batch Certificate of Analysis: A Base Oil Buyer’s Checklist
Understand what a base oil product sheet describes, what a batch COA should identify, and what to compare before accepting an offer.
Two documents, two questions
A technical data sheet (TDS) helps identify a proposed base oil grade and decide whether it merits further review. A certificate of analysis (COA) records measurements for an identified batch or shipment. When an agreed quality specification sets limits, buyers should compare the assigned material against those limits. Representative values on a product sheet are not evidence that a particular shipment passed a batch test.
Read the grade and the measurement together
Match the producer, product name, grade, document revision, and intended application with your purchase specification. SN150, 150N, and a Group III description are useful names, but none is a complete list of measured properties. For each property, read the unit, test temperature, method, and any stated acceptance range. ASTM D445 describes a method for measuring kinematic viscosity; the result still needs its temperature and unit. An ISO VG classification has a distinct basis under ISO 3448. Do not derive a numerical specification from the grade name alone.
Connect the COA to the material offered
For a proposed shipment, request a COA identifying the batch or tank, sampling point and date where relevant, results, units, test methods, and issuing party. Check that its batch corresponds to the material actually offered for loading or delivery. Compare results against the accepted contractual specification, and ask for clarification where a limit, method, or batch link is missing. Keep the safety data sheet separate: it addresses handling hazards and does not replace quality acceptance.
Resolve differences before acceptance
If supplier and receiver results differ, establish whether the samples, methods, and decision rule are comparable before declaring conformity or nonconformity. ISO 4259-2:2026 addresses use of petroleum test-method precision in conformity decisions. Agree the applicable method and dispute procedure in the commercial documents. A missing COA or an unapproved alternative calls for technical review.
Send a reviewable request
State the grade or application, required properties and limits, quantity and unit, packaging, destination, and documents needed. ALFAISAL can assess a documented request and respond with a proposal that identifies the actual product and acceptance conditions; an enquiry alone confirms neither stock nor price.
Primary references
These explain methods and trade terms. They do not certify a particular ALFAISAL product or shipment.
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