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Short answer: anhydrous sodium sulfate (Na2SO4, CAS 7757-82-6) is not classified as hazardous under GHS in the large majority of supplier notifications: 4,127 of 4,277 reports in the ECHA C&L Inventory, as aggregated by PubChem, say it does not meet the criteria. A small minority of notifications carry H320 (eye irritation) and H370 (organ damage). Because suppliers differ, the safety data sheet (SDS) that came with your bottle governs your lab. The main chemical hazard is incompatibility with aluminium, magnesium and strong acids. Similar-sounding names (sodium persulfate, sodium laureth sulfate) are classified very differently.
This page is for lab staff and EHS officers who need to read a sodium sulfate SDS quickly and compare it with the sheets for look-alike sulfates. It summarises public database records (PubChem, which aggregates ECHA C&L notifications and ICSC-style data, read 2026-11-08); it does not replace the SDS from your supplier.
Definition and scope
Sodium sulfate is the disodium salt of sulfuric acid. PubChem lists many synonyms for it, including disodium sulfate, salt cake and thenardite (the mineral form), and also Glauber’s salt, the name conventionally used for the decahydrate. Suppliers sell anhydrous, decahydrate and solution grades, and each has its own SDS, so check which form you hold. The anhydrous grade is hygroscopic, which matters for storage below.
What a sodium sulfate SDS says, section by section
An SDS follows the 16-section GHS layout (see how to read a safety data sheet and OSHA SDS requirements). The points below follow the sections people most often look for, using the PubChem record for sodium sulfate (CID 24436).
Hazard identification: GHS classification and H/P statements
PubChem reports that 96.5% of the 4,277 aggregated reports (10 notifications) say the substance does not meet GHS hazard criteria. Only 150 reports carry hazard codes. The minority notification shows the signal word Danger with H320 (causes eye irritation) and H370 (causes damage to organs), plus precautionary statements including P260, P264, P270, P305+P351+P338, P308+P316, P321, P405 and P501. For how these codes work, see GHS classification of chemicals.
Fire-fighting
Sodium sulfate is not combustible, though irritating or toxic fumes can form in a fire.
First aid (general information, not individual medical advice)
The ICSC-style entries summarised by PubChem give: inhalation, fresh air and rest; skin contact, rinse then wash with soap and water; eyes, rinse for several minutes, remove contact lenses if easy to do, then seek medical attention; ingestion, give one or two glasses of water. Follow your own SDS and site emergency procedure.
Handling, PPE and storage
PubChem’s spill-response entries name tight-fitting safety goggles, rubber gloves and protective clothing, with eye protection tested to NIOSH (US) or EN 166 (EU). Store with the container tightly closed in a dry, well-ventilated place; the substance is hygroscopic, and the German TRGS 510 storage class given is non-combustible solids. For the decahydrate, the record says keep well closed in a cool place.
Stability and incompatibilities
Incompatible materials are strong acids, aluminium and magnesium. The record states a violent reaction with aluminium, a violent reaction with magnesium, and that sodium sulfate and aluminium will explode at 800 °C. Segregation guidance is in chemical storage compatibility and segregation rules.
Disposal
The record advises recycling or returning unused material, offering surplus to a licensed disposal company, treating contaminated packaging as unused product, and never discharging directly to sewers or surface waters. Recovered sodium sulfate may be landfilled, subject to local rules.
Why suppliers’ classifications differ
PubChem notes that information may vary between notifications depending on impurities, additives and other factors, and that only about 3.5% of reports (150 of 4,277) carry hazard codes, while the rest state that the criteria are not met. The practical consequence is that two bottles of sodium sulfate from different suppliers can carry different hazard sections, and an SDS with H320 and H370 is not an error by default. Treat the sheet shipped with your product as the one for labelling and training.
Manufacturer SDSs for anhydrous sodium sulfate, compared
Searchers often want the supplier PDF itself. Two manufacturer sheets were read in full on 2026-11-08; their classifications differ, which illustrates the point above.
| Supplier and product | SDS revision read | Classification in Section 2 | Incompatibilities (Section 10) |
|---|---|---|---|
| Ricca Chemical, Sodium Sulfate, Anhydrous, ACS Reagent Grade (RDCS0850) | 2026-05-06, written to OSHA HCS 2024 | Not categorized as hazardous in any GHS hazard class; no pictogram, signal word or hazard statements | Aluminum and magnesium (explode at 800 C in combination with sodium sulfate); strong mineral acids and bases |
| Flinn Scientific, Sodium Sulfate (SDS #760) | 21 January 2014 (the PDF read is a copy of the sheet; check the Flinn page for the current revision) | Signal word Warning; acute toxicity, dermal, Category 5 (H313, may be harmful in contact with skin) | Strong acids, aluminum and magnesium |
Two sheets for the same compound therefore differ on whether any GHS hazard class applies at all. The sheets of other suppliers (Sigma-Aldrich/MilliporeSigma, Fisher Scientific and others) were not read for this page, so their classifications are not stated here; look up the sheet for your exact catalogue number on the supplier’s site.
Sodium sulfate vs sodium persulfate vs sodium laureth sulfate
All three names contain “sodium” and “sulfate”, but they are different substances. Aggregated ECHA C&L data in PubChem (read 2026-11-08):
| Substance (PubChem record) | Aggregated classification | Hazard statements reported |
|---|---|---|
| Sodium sulfate (CID 24436) | Not classified in 96.5% of 4,277 reports | Minority notification: H320, H370 |
| Sodium persulfate (CID 62655) | Danger; 3,211 of 3,253 reports carry hazard codes (1.3% say not classified) | H272 (oxidizer), H302, H315, H317 (skin sensitizer), H319, H334 (respiratory sensitizer), H335 |
| Sodium laureth sulfate (CID 23665884) | Danger in the larger notification; 52 reports from 2 notifications | H315, H318 (serious eye damage); other notification H315, H319 |
The comparison shows why one sulfate’s sheet cannot stand in for another: persulfate is an oxidizer and a skin and respiratory sensitizer, and laureth sulfate carries an eye-damage classification in its main notification, while sodium sulfate is mostly unclassified.
Where it matters for labs
- Keep sodium sulfate away from aluminium and magnesium, and from strong acids.
- Do not substitute a sodium sulfate SDS for sodium persulfate or laureth sulfate stock, or the reverse.
- Record the physical form (anhydrous, decahydrate, solution) on the inventory entry, since sheets are issued per product.
- Dispose of surplus through a licensed waste route rather than the drain; see chemical waste disposal procedures.
Common misunderstandings
- “Not classified” does not mean no precautions. The record still lists goggles, gloves and incompatibilities.
- One supplier’s SDS is not the whole picture. The aggregated data show a small minority classification.
- MSDS and SDS name the same document family. The older MSDS name was replaced by the 16-section SDS format.
FAQ
What does sodium sulfate do to you?
Most aggregated notifications classify it as not hazardous. A minority list eye irritation (H320) and organ damage (H370), and the first-aid entries cover rinsing eyes and skin and giving water after ingestion. This is general information, not medical advice; follow your SDS.
Is sodium persulfate hazardous?
Yes. In the PubChem aggregate, 3,211 of 3,253 reports carry hazard codes, including H272 (oxidizer), H302, H317 and H334 (skin and respiratory sensitizer), with the signal word Danger. That differs sharply from sodium sulfate.
What are the safety data sheets for sodium laureth sulfate?
Sheets vary by product and supplier. The PubChem record for sodium laureth sulfate reports H315 and H318 in its larger notification (52 reports, 2 notifications) and H315 with H319 in the other. Use the SDS for your specific product.
What is the common name for anhydrous sodium sulfate?
PubChem lists salt cake and the mineral name thenardite among its synonyms. Glauber’s salt is the traditional name for the decahydrate.
Where do I get the SDS PDF?
From the supplier of your product, which issues one per product and grade; direct links to the Ricca Chemical and Flinn Scientific sheets are in the comparison table above. For help locating one, see how to get an SDS.
Sources
- PubChem, Sodium Sulfate (CID 24436), Safety and Hazards, read 2026-11-08.
- PubChem, Sodium persulfate (CID 62655), GHS Classification, read 2026-11-08.
- PubChem, Sodium laureth sulfate (CID 23665884), GHS Classification, read 2026-11-08.
- OSHA, Hazard Communication Standard: Safety Data Sheets (OSHA 3514).
