A research supplier usually publishes two documents for each catalog item: a certificate of analysis and a safety data sheet. They are often filed side by side, emailed together, and linked from the same product page, so they are easily mistaken for two versions of one thing. They are not. A certificate of analysis reports what a specific lot was measured to contain. A safety data sheet describes the hazards of the material and how to handle, store, transport and dispose of it, whatever lot is in the vial.
The practical question for a store operator or a QC reviewer is this: which parts of the safety data sheet carry the most risk if they are wrong, and how do you keep the two documents from contradicting each other? This post walks through the sixteen sections and marks the ones small suppliers most often get wrong.
Where the sixteen-section format comes from
The safety data sheet (SDS) format is set out in the Globally Harmonized System of Classification and Labelling of Chemicals (the GHS), maintained under the United Nations. In the United States, the OSHA Hazard Communication Standard (29 CFR 1910.1200, often called HazCom) adopts the GHS approach and specifies the section order in its Appendix D. The headings are fixed and appear in the same sequence on every compliant sheet:
- Identification
- Hazard(s) identification
- Composition/information on ingredients
- First-aid measures
- Fire-fighting measures
- Accidental release measures
- Handling and storage
- Exposure controls/personal protection
- Physical and chemical properties
- Stability and reactivity
- Toxicological information
- Ecological information
- Disposal considerations
- Transport information
- Regulatory information
- Other information, including the date of preparation or last revision
OSHA requires all sixteen headings to be present, but it does not enforce the content of sections 12 through 15, because those topics fall under other agencies (environmental, transport and other regulators). They still matter: a courier or an institutional safety office may rely on section 14 or 15 directly.
The fixed order is the point: a laboratory worker handling a spill should find section 6 in the same place on any supplier's sheet. Reordering, merging or renaming sections undermines that.
The sections a research supplier must get right
Every section matters, but in a reagent catalog a handful carry most of the errors and most of the consequences.
Section 1: Identification
This section names the product identifier as it appears on the label, the supplier's name, address and telephone number, an emergency telephone number, and the recommended use and restrictions on use. For a research supplier, the recommended use is laboratory research, and the restriction should say so plainly. The product identifier must match the vial label and the catalog listing exactly. A sheet whose identifier differs from the label by a suffix, a pack size or an old catalog number breaks the link that lets a reader confirm they are holding the right document.
Section 2: Hazard(s) identification
This section gives the GHS classification, signal word, hazard statements, pictograms and precautionary statements. The classification has to come from an actual evaluation of available data. For many research materials the honest position is that the substance has not been fully characterized, and the sheet should state that its hazards have not been thoroughly investigated rather than implying a clean result. Copying "not a hazardous substance" from another supplier's sheet without a basis is a common problem in small catalogs.
Section 3: Composition/information on ingredients
This lists the chemical identity, common names, and where available the CAS number and concentration of each hazardous ingredient. When a product is a mixture, such as a reference material supplied with a buffer salt or a counterion, the composition should reflect that. Do not paste the purity figure from a certificate of analysis here. Section 3 describes the product as a type; the measured purity of lot 2407 belongs on that lot's certificate.
Section 7: Handling and storage
This is where the SDS most often contradicts the product page. If the catalog says to store a lyophilized research peptide at minus 20 degrees Celsius, protected from light and moisture, section 7 should say the same thing, including incompatible materials and container conditions. A sheet that says "store in a cool, dry place" next to a listing that specifies freezer storage leaves the laboratory with two instructions and no way to choose.
Section 8: Exposure controls/personal protection
This covers occupational exposure limits where they exist, engineering controls such as a fume hood or a ventilated balance enclosure, and personal protective equipment. For fine powders weighed on an analytical balance, the realistic concern is airborne dust, and the controls should match that task.
Section 16: Other information
Section 16 carries the date of preparation or last revision. Under HazCom, when a supplier becomes aware of significant new information about a hazard or about ways to protect against it, that information must be added to the SDS within three months. A revision date and a version number let a reader tell whether the copy in their binder is current.
How an SDS differs from a certificate of analysis
The two documents answer different questions, and keeping them apart avoids most cross-contamination between them.
| Safety data sheet | Certificate of analysis | |
|---|---|---|
| Question answered | What are the hazards and how is it handled safely? | What was this lot measured to be? |
| Scope | The product, across all lots | One lot or batch |
| Governing framework | GHS, OSHA HazCom in the US | The supplier's specification and the methods used, often validated in line with ICH Q2 |
| Key content | Classification, controls, storage, disposal, transport | Identity, purity, test methods, acceptance criteria, results, lot number, test date |
| When it changes | When hazard or protective information changes | Every new lot |
Section 9 of the SDS is the usual place where the boundary blurs. It lists physical and chemical properties such as appearance, odor, melting point and solubility. These are typical properties of the material, not test results for a lot. If a certificate of analysis reports the appearance of a specific lot as "white lyophilized powder", that is a measured observation for that lot; section 9 can describe the expected appearance, but it should not quote lot results or a purity percentage as if they were properties of the product.
The opposite error also occurs: a certificate of analysis that includes hazard statements or storage language copied from an old SDS. When those drift apart, a reviewer sees two documents from the same supplier giving different instructions. Keep storage and hazard language in the SDS and product page, and keep the certificate focused on lot identity, methods and results. More on certificates is on the blog.
Keeping the documents consistent across a catalog
Most inconsistency comes from maintenance rather than the first draft. A few habits help:
- One source of truth for storage. Decide the storage condition once per product and feed it into the SDS, the label and the product page from the same record.
- A controlled template. Build every sheet from one template with all sixteen headings in order, so no section is dropped when a product is added.
- Name the identifier once. Use the same product identifier on the label, the SDS, the certificate and the listing.
- Record revisions. Keep a revision history with the date, version and a line describing what changed, and replace the downloadable file when the sheet changes.
- Link the right file. Check that each product page links to its own SDS, not a sibling product's sheet reused as a placeholder.
Checklist before you publish an SDS
- All sixteen sections present, in GHS order, with the standard headings.
- Section 1 identifier matches the label and listing; recommended use states laboratory research; supplier contact and emergency number are current.
- Section 2 classification has a stated basis, or the sheet says plainly that the hazards have not been fully investigated.
- Section 3 describes composition, including any counterion or buffer component, with no lot purity figures.
- Section 7 storage matches the product page and label exactly.
- Section 8 controls fit the real handling task, such as weighing a fine powder.
- Section 9 lists typical properties, not lot results.
- Sections 12 through 15 are completed, or state that data are not available, rather than left blank.
- Section 16 shows a revision date and version, and the file linked from the product page is that version.
- The certificate of analysis for each lot references the same product identifier and carries lot-specific results only.