Technical Data Sheet
Technical Grade
| Test | Specification | Typical | Method | Source |
|---|---|---|---|---|
| Assay (Na2S2O5) | 98.0 – 100.0 % | 99.0 % | — | Supplier specification |
| Iron (Fe) | 0.0 – 7.0 ppm | 3 ppm | — | Supplier specification |
| Sodium sulfite (Na2SO3) | 0.0 – 1.0 % | 0.3 % | — | Supplier specification |
| Sulfur dioxide (SO2), available | Min. 64.0% | 65.7% | Iodometric titration (I2 / Na2S2O3) | Interpreted |
| Water insoluble matter | Max. 0.05% | 0.005% | Gravimetric; 10% solution filtered through tared crucible, dried at 105 C | Interpreted |
| Screen size, through 20 mesh (U.S. Sieve) | Min. 95% | 99.2% | ASTM E11 sieve analysis | Interpreted |
Specification values are guaranteed limits. Typical values are representative of production lots and are not guaranteed. Lot-specific certificates of analysis ship with every order.
| Grade | Concentration | Typical Assay | SKU | TDS |
|---|---|---|---|---|
| This grade Technical Grade | — | — | current | current |
| ACS Grade | — | — | sodium-metabisulfite-acs-grade | View TDS → |
| Food Grade | — | — | sodium-metabisulfite-food-grade | View TDS → |
Typical assay shown is the rolling-window mean from the sibling product's most recent lots. Grade selection drives downstream end-use — verify the sibling grade matches your specification before substitution.
| Property | Value | Source |
|---|---|---|
| Appearance | Free flowing, white to slightly yellow, fine granular crystal having a characteristic odor of sulfur dioxide | Supplier specification |
| Odor | In the presences of traces of water, it develops an odor of sulfur dioxide | Published reference |
| pH | 3.5 to 4.5 | Supplier specification |
| Density | 1.4 (NIOSH, 2024) - Denser than water; will sink | Published reference |
| Boiling Point | Decomposes (NIOSH, 2024) | Published reference |
| Melting Point | greater than 302 °F (Decomposes) (NIOSH, 2024) | Published reference |
| Solubility (water) | Clear and colourless solution | Supplier specification |
| Material | Rating | Conditions | Source |
|---|---|---|---|
| HDPE (bags with liners) | Compatible | dry solid as supplied in manufacturer's standard 25/50/1000 kg packing; no concentration or temperature stated | shaktichemicals.com |
| polyethylene (sealed bags) | Compatible | dry granular solid as supplied in manufacturer's standard packaging; no concentration or temperature stated | essecousa.com |
| polypropylene (bulk sacks) | Compatible | dry granular solid as supplied in manufacturer's standard packaging; no concentration or temperature stated | essecousa.com |
Compatibility is drawn from published manufacturer and supplier documentation for this product; each rating is sourced. Confirm against your specific duty cycle before equipment selection.
Transport descriptions reflect 49 CFR 172.101 lookup at time of publication. Sourced data: ECHA CLP Annex VI for harmonised classifications, NIOSH Pocket Guide for REL/IDLH, OSHA Z-Tables for PEL. Always verify against the latest regulatory text before shipment-critical decisions.
One zipped download containing the TDS, SDS, latest lot COA (when available), and a fresh Letter of Continuing Guaranty for Sodium Metabisulfite - Technical Grade. Every file included is SHA-256 hashed and listed in a manifest your QA team can audit.
Applications are drawn from published manufacturer and supplier documentation; each is sourced. Suitability for a specific use is the buyer's to confirm.
For full hazard, PPE, and emergency response guidance, refer to the Safety Data Sheet (SDS) for this product. The SDS controls in all cases where guidance differs.
Not regulated for transport.
Confirm against shipping documents and carrier requirements before tender.
Last reviewed 2026-07-17 by Andre Taki, DOT Hazmat Specialist.
| Version | Date | Change | Trigger |
|---|---|---|---|
| 1.1 | 2026-07-17 | Canonical data re-verified: 7 fields updated against independent vendor SDSs, CLP Annex VI, 49 CFR, and OSHA HazCom 2024 (GHS classification, hazard/precautionary codes, signal word, physical properties as applicable).
| canonical_change |
| 1.0 | 2026-05-20 | Initial URL-first TDS published from canonical chemistry registry. | initial |
This Technical Data Sheet is provided for technical reference. The Safety Data Sheet (SDS) controls in all cases where guidance differs. Values reflect Alliance Chemical canonical data at time of generation; subsequent revisions are recorded in the Revision History above.