A Technical Data Sheet specifies the typical performance, physical, and chemical properties of a chemical product as the manufacturer formulated it. TDS is forward-looking and product-level: it tells the buyer what the product is supposed to be. The COA is backward-looking and batch-level: it certifies what a specific manufactured batch actually was. The SDS is hazard-focused: it tells the buyer how to handle the product safely. All three documents are needed for routine chemical procurement, and they answer different questions.
What a TDS contains
A typical TDS for an industrial chemical includes:
- Product identification, name, CAS number, grade, intended use
- Typical physical properties, appearance, density, melting/boiling point, vapour pressure, viscosity
- Typical chemical properties, purity range, moisture content, ash content, key impurity ranges
- Performance specification, application-relevant properties (for caustic soda, alkali content; for citric acid, anhydrous content; for TiO2, oil absorption and tinting strength)
- Packaging and storage, packaging units, shelf life, storage conditions
- Application notes, recommended uses, dilution rates, common formulations
The TDS is what a buyer reads when deciding whether the product fits their formulation. The buyer’s R&D or quality team typically signs off on the TDS during supplier qualification, and subsequent orders reference it.
TDS vs COA vs SDS
| Document | What it certifies | Per-product or per-batch | Issued by |
|---|---|---|---|
| TDS | Typical product properties as manufactured | Per-product | Manufacturer |
| COA | Actual measured values for a specific batch | Per-batch | Manufacturer or third-party lab |
| SDS | Hazards, handling, transport, regulatory status | Per-product | Manufacturer |
The three documents work together. The TDS sets the buyer’s expectation. The COA confirms whether the specific batch shipped meets that expectation. The SDS guides how to handle the cargo safely on arrival.
The TDS-vs-COA gap that gets buyers burned
The TDS gives typical or specification ranges. The COA gives actual measured values for the batch shipped. A wide gap between TDS specification and COA actual is the most common quality failure on Chinese chemical imports.
Example. A TDS for industrial-grade caustic soda flakes specifies:
- NaOH content: 99.0 percent minimum
- Na2CO3 content: 0.4 percent maximum
- Iron (Fe2O3): 0.005 percent maximum
The COA for the actual shipped batch shows:
- NaOH content: 98.4 percent (below TDS minimum)
- Na2CO3 content: 0.6 percent (above TDS maximum)
- Iron: 0.008 percent (above TDS maximum)
The buyer ordered against the TDS, not the COA. The cargo is on the water. The buyer’s downstream process is sensitive to NaOH content and iron contamination. The shipment is technically out of spec on three lines.
The lesson the trade learns the hard way: the TDS is the contractual specification only if the purchase order explicitly says so. Otherwise the contract spec is whatever was written into the PO. Always write the spec ranges directly into the purchase order, with explicit reject triggers (“NaOH below 99.0 percent or iron above 0.005 percent triggers rejection at port”). Otherwise the buyer is arguing with the factory after the cargo has shipped.
When the TDS is missing or vague
Smaller Chinese factories sometimes have weak TDS documentation. The TDS may be a one-page leaflet with a few headline numbers. If the TDS is too thin to write a meaningful purchase order against, two options:
- Ask the factory for the COA from the last three batches shipped. Recent COAs reveal what the factory actually produces, more reliably than the TDS.
- Insist on a pre-shipment third-party inspection by SGS or Bureau Veritas with the inspector running the spec tests against the agreed PO spec. Costs USD 400 to USD 1,000 per inspection but closes the documentation gap.
What a TDS does not tell you
A TDS does not certify:
- The composition of any specific shipped batch
- Compliance with destination regulatory regimes (REACH, TSCA, AICIS require separate filings)
- Hazard classification (the SDS covers this)
- Country of origin (the Certificate of Origin covers this)
Related terms
COA is the per-batch certification. SDS is the hazard-focused companion document. MOQ economics often determine whether a buyer can afford to test against the TDS via a small trial order.