SDS, COA and TDS: three documents, three different jobs

An SDS, a COA and a TDS answer different procurement questions. The SDS communicates hazards and safe-use information. A COA reports results against stated criteria for an identified batch. A TDS describes technical properties or application information for a product or grade. None of the three should automatically be treated as a substitute for the others.

Safety Data Sheet: hazard communication

Check that the SDS identifies the offered material and responsible supplier, and that its revision and jurisdiction match your requirements. The standardized format uses 16 sections; the applicable obligations still depend on the jurisdiction. OSHA hazard communication questions and answers explains the US framework, while ECHA guidance on safety data sheets describes European supply-chain context.

Start with Sections 1 and 2 for product and hazard identification, then check composition, handling, exposure controls, physical properties, stability, toxicology, transport and revision information as relevant to your review. An SDS communicates hazards; it does not certify a batch against a purchasing specification.

Certificate of Analysis: the named batch

Start with the product, grade, issuer and batch reference. Compare the listed tests, methods, acceptance limits and reported results with the agreed specification. A result without a limit may be informative but does not show whether the batch meets your requirement.

A sample COA can support supplier evaluation. It should not be confused with the analysis for a future shipment. The final batch document needs to correspond to the material supplied and should be reviewed with the purchase specification.

Technical Data Sheet: technical context

A TDS can describe processing, application properties and typical technical values. Read the product grade, test conditions, qualification notes and revision. Typical values should not automatically be treated as guaranteed acceptance limits.

Where an application depends on a technical value, ask whether the value is typical or controlled, which test method applies and whether it will appear in the agreed specification or batch documentation.

Check the same identity across every document

Compare the product name, CAS number or composition, concentration, grade and supplier across the quotation, SDS, TDS and COA. Ask for an explanation when identifiers, physical form, revisions or responsible organizations differ.

Build a document request around the decision

For preliminary safety review, request the current SDS for the offered product and responsible supplier. For technical fit, request the relevant specification or TDS. For batch acceptance, define the required tests and later review the batch-specific COA. Destination-specific documents may require a separate check.

The quality and documentation guide provides a compact comparison table. You can also request documents with your chemical enquiry.