A technical data sheet (TDS) describes product characteristics, a certificate of analysis (COA) records batch testing, and a safety data sheet (SDS) communicates safety information. REACH is a chemicals regulatory framework covering obligations such as registration, evaluation, authorisation and restriction. These serve product understanding, quality assessment, safe use and regulatory management respectively, and should not all be treated as one kind of quality certificate.
Distinguish the four concepts first
| Term | Meaning | Main purpose |
|---|---|---|
| TDS: Technical Data Sheet | Technical data sheet | Describes product characteristics, typical parameters and uses |
| COA: Certificate of Analysis | Certificate of analysis or batch analytical report | Lists tests and results for the corresponding batch |
| SDS: Safety Data Sheet | Safety data sheet | Communicates hazards, protection, storage, transport and emergency information |
| REACH | Registration, Evaluation, Authorisation and Restriction of Chemicals regulation | Sets relevant obligations in the applicable market; it is not an ordinary quality certificate |
These terms often appear together because buying and using chemicals involves technical, quality, safety and regulatory questions at the same time. They are not the same type of document.
TDS: understanding the product, not measurements for every batch
A TDS may contain appearance, physical properties, technical parameters and suggested uses. Typical values describe common characteristics; they are not necessarily results for every batch or automatically guaranteed limits. The document’s own labels establish the nature of a value.
For example, a viscosity value needs a temperature condition, and melting or boiling points also have associated measurement conditions. Listing a use establishes relevance to an application, not suitability for every downstream formulation.
COA: linking results to a specific batch
A COA generally includes the product, batch number, tests, results and corresponding specifications. Its value lies in connecting results with specific material, rather than merely having certificate in its name.
When reading a COA, first match the product, grade and batch number, then examine each parameter’s specification limit, result and test method. A measured value, a conformity statement and ‘not detected’ convey different information and need to be understood according to the report’s labels.
Hypothetical example, not an official company document: a TDS lists typical water of 12 mg/kg, the specification limit is ≤20 mg/kg, and a batch COA reports 16 mg/kg using a comparable method. This result is above the typical value but below the limit, with no contradiction. A different batch at 23 mg/kg exceeds the limit and should be handled according to that batch result.
Learn more about purity, detection limits and reading test reports
SDS: supporting safe chemical use and handling
An SDS provides information on hazards, first aid, firefighting, spill response, handling and storage, exposure control and transport. Review handling and storage requirements before storage, exposure controls and personal protection before use, and transport information when arranging shipment, confirming the requirements against applicable rules.
Composition, jurisdiction and version affect the contents. An SDS for one substance or grade cannot be reused merely by changing its name. Transport classification also does not replace health and handling precautions in other sections. Where applicable, an extended SDS includes exposure scenarios.
Using the SDS sections specified by the US Occupational Safety and Health Administration (OSHA) as an example, section 4 covers first aid, 5 firefighting, 6 accidental release, 7 handling and storage, 8 exposure controls and personal protection, and 14 transport information. The relevant section can be located by activity; confirm the document’s applicable jurisdiction and version before use.
REACH: regulatory requirements, not quality certification
REACH applies in the European Union and European Economic Area and concerns registration, evaluation, authorisation and restriction of chemical substances. Registration focuses on substance information and responsibilities for safe use, not certification of purity, batch quality or battery performance.
Obligations depend on the substance, quantity, use and company’s role in the supply chain. Manufacturers, importers and downstream users have different roles. Eligible companies outside the applicable region may also fulfill relevant registration obligations through an only representative established there. Coverage of a specific supply cannot be determined from a REACH certificate or number alone.
To understand actual registration and supply coverage, relate the documentation to the substance, legal entity, use and supply relationship, and establish the obligations of each party.
Read the documents together
The product and grade in the TDS, batch number and results in the COA, and identity and hazard information in the SDS should correspond. The manufacturer, supplier and testing organization may differ. What matters is that their roles are accurate and clear, not that every document bears exactly the same company name.
When documents are updated, check for changes to version, applicable product and scope of use. A COA cannot replace an SDS, an SDS cannot establish batch purity, and REACH registration cannot replace quality testing. Distinguishing these purposes reveals what each document actually provides.
References
ECHA: safety data sheets and exposure scenarios
US OSHA: 29 CFR 1910.1200 Appendix D, SDS sections and content
US OSHA: 29 CFR 1910.1200(g)(2), particularly Note 1 and Note 2
ECHA: responsibilities of non-EU companies and only representatives
US regulatory note: 29 CFR 1910.1200(g)(2) specifies SDS section numbers, headings and sequence. Note 1 requires the headings for sections 12–15 to be retained; Note 2 states that OSHA does not enforce the specific information requirements for these sections. This enforcement scope does not remove transport or other obligations under applicable regulations, and does not represent the full requirements of other jurisdictions.