The short answer
An SDS explains how to handle a chemical safely. A TDS describes the product's typical or guaranteed technical specifications. A CoA reports the measured results for one specific production batch. These documents answer different questions and one cannot normally replace another.
A professional purchase should start by defining the intended application, required grade, acceptable limits, documentation language and whether batch-level evidence is needed. The product name alone is rarely enough to establish suitability.
What is an SDS?
The Safety Data Sheet communicates hazard and safe-use information. Under REACH, its format and content cover matters such as identification, hazards, composition, first aid, firefighting, handling, storage, exposure controls, transport and disposal. ECHA states that recipients should identify and apply the appropriate risk-management measures described in the document.
An SDS is therefore a safety and regulatory document. It does not certify that a particular batch meets an analytical purity limit, and it should not be treated as a substitute for a product specification or batch analysis.
- Check that the product and supplier identifiers match the order.
- Check the revision date and required language.
- Review classification, storage, incompatibility and transport information.
- Confirm that the intended use is covered by the supplied safe-use information.
What is a TDS?
A Technical Data Sheet summarises the product's technical characteristics and intended applications. Depending on the product, it may contain assay limits, density, water content, residue, colour, stabiliser information, recommended conditions or other specification values.
A TDS is useful during product selection because it lets the buyer compare the method requirement with the supplier's stated specification. However, the buyer should distinguish guaranteed limits from merely typical values and confirm the applicable document revision.
What is a CoA?
A Certificate of Analysis is linked to a defined batch or lot. It normally identifies the product and batch and reports actual test results against selected specification limits. This makes the CoA particularly important for incoming inspection, traceability, audits and regulated workflows.
A generic or sample CoA can show the document format, but it does not prove the results of the batch that will be delivered. Where batch evidence matters, request the CoA for the supplied lot and verify that the batch number matches the label and delivery documents.
SDS, TDS and CoA compared
- SDS — answers: What are the hazards and how should the product be handled safely?
- TDS — answers: What technical specification and intended performance does the product have?
- CoA — answers: What values were measured for this specific batch?
- SDS is not evidence of batch purity; TDS is not a safety instruction; CoA is not a complete safe-handling guide.
EU and Türkiye considerations
For the EU supply chain, ECHA explains when an SDS must be provided and when exposure scenarios may need to accompany it. The document should be updated when new hazard information or stricter risk-management measures become available.
Türkiye's chemical authority states that labels and safety data sheets for imported hazardous substances and mixtures must be prepared in Turkish. Other languages may be added, but the Turkish information must be present. This language requirement should be checked before shipment, not after the material reaches the receiving site.
Procurement checklist
- Define product name, CAS number, grade, concentration and packaging.
- Record the method or application and its critical acceptance limits.
- Request the current SDS in the required language.
- Compare the TDS specification with the method requirement.
- State whether a batch-specific CoA must be available before dispatch.
- Match product code and batch number across label, CoA and delivery record.
- Verify shelf life, storage temperature and transport restrictions.
- Archive the received document revisions with the purchase record.
