Datasheet vs SDS vs COA: Which Peptide Document Proves What?

Published 2026-10-23 · Last updated: 2026-10-23 · By: Index Peptides technical team

A datasheet states what a product is specified to be, a safety data sheet (SDS) describes its hazards and how to handle, store and transport it, and a certificate of analysis (COA) reports what one manufactured batch actually measured. Only the COA is batch-specific, so only the COA can tell you anything about the lot in your hands. This page explains the job of each document, what each one can and cannot establish, and the order in which to ask for them.

Research use only. Not for human or animal consumption.

Three documents, three jobs

Chemical suppliers routinely issue all three documents, and buyers routinely confuse them. The quickest way to keep them apart is by scope: the datasheet and the SDS describe the product, while the COA describes one lot.

The distinction is standard across chemical supply. The laboratory-chemicals supplier Scharlab summarises it this way: the technical data sheet "provides the guaranteed values of the product specifications, while the Certificate of Analysis shows the actual values obtained for each manufactured batch", and an SDS is "a legal document detailing health, safety, and environmental risks, as well as necessary protective measures". The key word throughout is batch.

What a datasheet is, and why it cannot replace a COA

A datasheet, also called a technical data sheet, product data sheet or specification sheet, orients you to the product. It typically gives the compound name and identity reference (sequence, CAS number, molecular formula and molecular weight), the physical form, the specification limits the product is meant to meet and a storage condition. That is useful compound-level information, and it is the right place to confirm you are looking at the intended material.

What a datasheet does not do is record a measurement. A standing line such as "purity 98% or higher" is a specification: a statement of what the product is expected to meet. It reads the same on every copy of the sheet, for every batch, so it is not evidence about any of them. The same applies to "typical" values, which describe what batches usually look like rather than what this one measured. If a request for batch documentation is answered with a datasheet, the question about the batch has not been answered.

What an SDS is, and why it cannot replace a COA

An SDS is a hazard-communication document. It is organised into standard sections covering matters such as hazard identification, handling and storage, exposure controls and protective measures, disposal and transport information. Its audience is anyone who handles, stores or moves the material, and its purpose is safe handling in the laboratory and in transit.

An SDS says nothing about quality. It does not report purity, does not confirm identity and is not tied to a lot number. The presence of an SDS is therefore not evidence of quality, and the absence of one says nothing about purity or identity either. An SDS answers "how should this substance be handled?", not "what is in this vial?". Nor does an SDS, or any other document on this page, indicate that a material is suitable for anything beyond in-vitro laboratory research.

What a COA proves, and where it stops

A COA reports the measured results for one batch: the lot number, the test date, the analytical method behind each result and the result itself, typically HPLC purity and, where that test was run, mass-spectrometry identity, along with the issuing laboratory. The fields are explained in what is a COA for a research peptide, and the layout of each section is walked through in anatomy of a peptide COA.

A COA has three limits worth keeping in mind:

1. It describes that lot only. It says nothing about the previous batch or the next one.
2. It proves only what it reports. A certificate with an HPLC purity figure and no identity result has not confirmed identity, however high the purity.
3. It describes your vial only when the lots match. The lot number on the certificate must match the lot number on the label.

The gap between a material being "tested" and a result being checkable is covered in what "lab tested" means.

What to ask for, and in what order

Each document has a place in the paperwork, and the order matters because each one answers a different question:

1. Datasheet first, for orientation. Confirm the compound, form and specification before you look at any batch.
2. SDS for handling. Keep it with your laboratory records for storage and handling, alongside the batch record for the material you hold.
3. The batch COA last, and most carefully. Ask for the certificate whose lot matches the vial you will receive, then read it against the datasheet. Does each measured result sit within the stated specification, and is each result attributed to a named method? The workflow is set out in request a batch COA by lot number.

The datasheet tells you what the product should be, the SDS tells you how to handle it, and only the COA tells you what this batch measured.

Where Index publishes batch documentation

Index Peptides publishes batch records and certificates at /coa, and the public lookup at /verify returns the record for a lot number so the certificate can be matched to the label. Read the published certificate for the exact lot, including which analytical results it actually reports.

What this page is not

It is not a guide to chemicals regulation and does not set out the legal requirements for any document. It explains what each document records so that each one is read for what it is.

FAQ

What is the difference between a datasheet and a COA?

A datasheet states the product's specification, the values the product is meant to meet, and reads the same for every batch. A COA reports the values one manufactured batch actually measured, with the lot number, method and test date. Only the COA is evidence about a specific lot.

Is a safety data sheet the same as a certificate of analysis?

No. An SDS communicates hazards, protective measures and handling, storage and transport information for the substance. It does not report purity, does not confirm identity and is not tied to a lot number, so it cannot stand in for a COA.

Can a purity figure on a datasheet be treated as a batch result?

No. A purity line on a datasheet is a specification or a typical value, repeated on every copy of the sheet. A batch result appears on a COA, attributed to a named method and tied to a lot number that matches the vial label.

Which document should match the lot number on my vial?

The certificate of analysis. Datasheets and SDSs describe the product in general and usually carry no lot number. The lot number on the COA should match the label character for character; if it does not, the certificate describes a different batch.

Where does Index Peptides publish batch documentation?

Batch records and certificates are published at /coa, and any lot number can be checked at /verify. Read the certificate for the exact lot, including which results it reports. Research use only. Not for human or animal consumption.

Research use only. Not for human or animal consumption.