TDS vs SDS vs CoA vs certificates: which document answers what

The table covers documents a chemical maker or distributor gives business customers under US OSHA HCS and EU REACH. It does not cover consumer labels, dangerous goods transport declarations, food contact or medical device declarations, or safety data sheet rules in other jurisdictions, which set their own content and triggers.

When should you use a TDS, SDS, CoA and certificate reference table?

Use a TDS, SDS, CoA and certificate reference table whenever a customer asks for "the documents" or asks a question that one of them should answer, so that you send the file that actually answers it. The five document families are the technical data sheet (TDS), the safety data sheet (SDS), the certificate of analysis (CoA), certificates and declarations (certificate of conformity, accredited test report, regulatory declaration), and the catalog.

The table is built for technical service, sales and quality staff at chemical makers and distributors, and for purchasing and quality staff at the buyer who review what arrives. It is most useful at four moments: a new customer onboarding pack, a supplier qualification questionnaire, a complaint where the customer quotes a TDS value against a lot result, and an audit where someone asks which document proves a claim.

Each row answers three things: the customer question in plain words, the document and section that answers it with the rule behind it, and what that document cannot prove. The third column matters most, because most document disputes start when a file is used to prove something it was never meant to prove, such as a typical TDS value treated as a lot guarantee. The editable Excel log, with the full table and a CSV header for import, is at the end of the page.

What is the difference between a TDS, an SDS and a CoA?

The difference between a TDS, an SDS and a CoA is what each one describes: a TDS describes the product's typical properties and use, an SDS describes its hazards and safe handling, and a CoA reports measured results for one lot. The three are not interchangeable even when they share a property such as viscosity or flash point.

The table below shows what each document covers, which rule sets its format and when it changes.

The key row is the first: an SDS and a TDS describe the product as a whole, and only a CoA describes the specific batch a customer received. Section 9 of a US SDS includes kinematic viscosity, pH and flash point (OSHA Appendix D, 2024), and a TDS may repeat them as typical values, but neither states what one delivered lot measured. A catalog sits beside the three: it lists the grades, pack sizes and product codes a maker sells, and it is evidence of what can be ordered, not of any property.

The full TDS, SDS, CoA and certificate reference table

The full TDS, SDS, CoA and certificate reference table lists 22 customer questions, grouped by the kind of answer they need: typical properties first, then hazards, lot results, compliance proof and finally questions no standard document answers. Read across each row: the middle column names the document and section and the rule behind it, and the right column says what the customer should not conclude from that document.

The row most often misread is lot conformity: only a CoA carrying the batch number on the customer's label answers whether that lot meets specification, and a TDS value never does. The second most misread row is transport: the SDS section 14 reports the dangerous goods classification, but the consignment is shipped under the transport rules the SDS names. A blank answer in the middle column of the last group is the point of the table: those questions need a trial, an agreement or a test, not a document.

The reference table maps customer questions to the document that answers them.

Which document proves a lot meets specification?

A certificate of analysis for that batch is the only one of these documents that proves a lot meets specification, and only for the tests it lists. ICH Q7, the good manufacturing practice guide for active pharmaceutical ingredients (APIs), says the certificate "should list each test performed in accordance with compendial or customer requirements, including the acceptance limits, and the numerical results obtained (if test results are numerical)" (ICH Q7, 2000, 11.42). It adds the batch number and release date, and an expiry or retest date where one applies (ICH Q7, 2000, 11.41).

Outside APIs, no single rule fixes CoA content, so the agreed specification decides which tests the CoA must carry. Check three things before you treat a CoA as proof: the batch number matches the container label, each property the customer cares about appears with its limit and result, and the test method named is the one in the specification.

A CoA is also not a substitute for all incoming checks. US drug manufacturing rules let a manufacturer accept a supplier's report of analysis "provided that at least one specific identity test is conducted on such component by the manufacturer" and the supplier's results are validated at intervals (FDA 21 CFR 211.84(d)(2), 2026). ICH Q7 recommends that the reliability of certificates of analysis be checked at regular intervals (ICH Q7, 2000, 7.31). Those rules bind drug makers; other buyers set incoming checks in their own quality agreements.

Which document answers a hazard or transport question?

The safety data sheet answers hazard, protection, emergency and transport questions, because its sections are fixed by law in the US and the EU. US OSHA requires the SDS to be in English and to carry 16 numbered sections in order, from identification to other information with the date of preparation or last revision (OSHA 29 CFR 1910.1200(g)(2), 2024). Section 2 holds the classification, section 3 the hazardous ingredients with CAS numbers, section 7 safe storage and incompatibilities, and section 8 exposure limits and protective equipment (OSHA Appendix D, 2024).

US enforcement stops at section 11. OSHA states that it "will not be enforcing information requirements in sections 12 through 15, as these areas are not under its jurisdiction" (OSHA 29 CFR 1910.1200, 2024). Ecological, disposal, transport and regulatory answers on a US SDS are still useful, but other agencies' rules govern them.

In the EU, the SDS format comes from REACH Annex II as replaced by Regulation (EU) 2020/878, and subsection 14.1 requires the UN number or ID number from the UN Model Regulations, IMDG, ADR, RID, ADN or ICAO Technical Instructions (Regulation (EU) 2020/878, 2020). The SDS therefore tells a customer how the product is classified for transport, while each shipment is declared under the modal rule that applies to it. An SDS describes the product, not one lot, so a hazard question about contamination in a specific delivery goes to the CoA and the complaint process.

When does a customer need a certificate instead of a CoA?

A customer needs a certificate instead of a CoA when the question is whether the product, process or system conforms to a named requirement, or when the customer needs someone other than the supplier's quality unit to attest it. A CoA reports measured results; a certificate or declaration states conformity.

Three kinds answer different questions. A supplier's declaration of conformity is a first-party statement; ISO/IEC 17050-1:2004, confirmed in 2025, sets its general requirements, and "the object of a declaration of conformity can be a product, process, management system, person or body" (ISO, 2025). A certificate is third-party: ISO defines certification as "the provision by an independent body of written assurance (a certificate) that the product, service or system in question meets specific requirements" (ISO, Certification). An accredited test report comes from a laboratory assessed against ISO/IEC 17025:2017, which accreditation bodies use "as the criteria for assessing and accrediting laboratories" (ISO, 2023).

Regulatory declarations sit beside them. Under REACH, a supplier of an article containing a candidate list substance above 0.1% weight by weight must give the recipient enough information for safe use, including at least the substance name (REACH Article 33, 2026). Ask for the exact requirement before you issue anything: "REACH compliant" or "certified" with no rule named cannot be answered by any single document.

Which customer questions does no TDS, SDS or CoA answer?

No TDS, SDS or CoA answers whether the product will work in the customer's process, whether it equals another maker's product, or whether the next lot will match the approved sample. These questions need a trial, a test or an agreement, and treating a document as the answer is the most common cause of a later complaint.

Fitness in the customer's process depends on the substrate, equipment, contamination and operating conditions, which no maker's document knows. The answer is a trial with success criteria agreed before it starts, measured by named methods.

Equivalence to another brand is a comparison under the same test methods and editions. Two TDS values for the same property often come from different methods or conditions, so they cannot be compared without that check. The answer is a side-by-side test, or the two makers' data on the same method at the same temperature.

Consistency of the next lot is a supply question. A CoA is issued for each batch on request (ICH Q7, 2000, 11.40), so it says nothing about the next one, and an SDS changes only with hazard information. The answer is an agreed specification with limits per property and a change notification clause in the supply agreement, so the customer hears of a formula, site or raw material change before it ships.

Root cause of a field problem is also outside these documents. The CoA and SDS are inputs to the investigation, not its conclusion.

How do you use the document reference table on a real customer question?

To use the document reference table on a real customer question, split the request into single questions, classify each by the kind of answer it needs, and log the document you send with what it cannot prove. The editable log has one row per question and these columns.

The table below previews every column in the log, with an illustrative example value for each.

Fill the log in that order. Classify before you search for a file, because the question type decides the document, not the file name. Copy the "cannot prove" text into the reply when a customer might over-read the document. Keep one row per question even when one file answers several, so that a later audit or complaint review can see which question each file answered, which revision went out and on what day. In Lubinpla, the Dataroom tags each stored file with one of six document types, TDS, SDS, CoA, Certificate, Catalog or Other, the same split this table uses.

What does an illustrative customer document request look like in the log?

An illustrative customer document request shows how one email becomes several log rows, each answered by a different document. The request below is invented for this example, and so are the product, lot and dates.

A customer writes: "Please send the documents for lot 24-117 of Coolant X. We need to confirm viscosity is in spec, that it is REACH compliant, what gloves our operators need, and that it will not attack our seals."

Split it into four questions. "Viscosity in spec for lot 24-117" is a lot result, answered by the CoA for batch 24-117 with the viscosity limit and result; the TDS viscosity is typical and does not answer it. "What gloves" is a hazard question, answered by SDS section 8 with the revision date logged. "REACH compliant" names no duty, so reply with the two that can be answered from documents: the registration numbers of the registered substances it contains, in SDS subsection 3.2.4, and the information duty for candidate list substances in articles under Article 33, which does not apply to a liquid mixture like this one. Ask which requirement the customer's procedure names.

"Will not attack our seals" has no document answer. Log it with the next step "seal compatibility test on the customer's elastomer", and say so in the reply rather than sending a TDS line about compatibility. The result is four log rows, three documents sent and one test proposed.

Where the TDS, SDS and CoA reference table does not apply

The TDS, SDS and CoA reference table does not apply outside US OSHA and EU REACH rules, to consumer products, or to sectors whose own rules define the CoA or the declaration. Check the local rule before you rely on any row for another market.

Jurisdiction comes first. Safety data sheet content and triggers in China, Japan, Korea, Canada and other markets are set by their own rules, with their own required content, language and update triggers. Regulated sectors come second. The CoA rows draw on ICH Q7 and 21 CFR 211.84, which govern active pharmaceutical ingredients and US drug manufacturing; food contact materials, medical devices, aerospace and automotive supply chains set their own declaration and inspection document formats.

The table also does not settle contracts. Which tests a CoA carries, how often it is issued and which certificates are required are commercial terms, and the supply agreement overrides any general reading here. TDS layouts differ by maker, so the TDS rows describe typical content, not a required format. Finally, the table answers which document to send, not whether that document is correct: an outdated SDS revision or a CoA for the wrong batch number fails every row, so check the date and batch number before anything goes out.