Industrial chemicals · Taylor, TXCertificate of Analysis
Sample Certificate of Analysis
Sodium Metabisulfite - Food Grade
Food Grade
Sample COA. Contact Alliance Chemical with your lot number to request a lot-specific COA.
- CAS number
- 7681-57-4
- Structure
Structure · PubChem - Grade
- Food Grade
- Assay specification
- Not less than 90.0% and not more than 100.5% of Na2S2O5
- Answer summary
Sample specification reference for Sodium Metabisulfite - Food Grade. Source-record results are reference values, not measurements for your lot.
Last reviewed 2026-07-17 by Andre Taki, Chief Commercial Officer, DOT Hazmat–certified (49 CFR 172.704).
Specifications
| Parameter | Specification | Source reference result | Test Method |
|---|---|---|---|
| Assay (Na2S2O5) | Not less than 90.0% and not more than 100.5% of Na2S2O5 | 95.12 % | — |
| Description / Appearance | Colorless crystals or a white to yellow, crystalline powder | Passes test | — |
| Arsenic (As) | 0.0 – 1.0 ppm | 0.11 ppm | — |
| Heavy metals (as Pb) | 0.0 – 10.0 ppm | 0.52 ppm | — |
| Identification | A 1:10 aqueous solution gives positive tests for Sodium and for Sulfite | Passes test | — |
| Insoluble matter | < 0.005 wt. % | 0.0017 % | — |
| Lead (Pb) | Not more than 2 mg/kg | 0.16 mg/kg | — |
| pH | 4.0-4.8 | 4.4 | — |
| Screen size, through 20 mesh (U.S. Sieve), % by weight | 92 - 100 % | 96.4 % | — |
| Selenium | < 5.0 ppm | 0.12 ppm | — |
| Chloride (Cl) | 0.0 – 0.02 % | 0.0069 % | — |
| Iron (Fe) | Not more than 10 mg/kg | 2.3 mg/kg | — |
| Sodium thiosulfate (Na2S2O3) | 0.0 – 0.04 % | 0.0072 % | — |
| Sodium sulfite (Na2SO3) | 0.0 – 0.6 % | 0.19 % | — |
| Mercury (Hg) | Not more than 1 mg/kg | 0.017 mg/kg | Cold vapour AAS (FCC Mercury Limit Test / AOAC 971.21) |
| Sulfur dioxide (SO2), available | Min. 65.0% | 66.1% | Iodometric titration (FCC assay procedure) |
| on no. 40 | 10 - 50 % | 26.3 % | — |
| through no. 100 | 0 - 15 % | 7.2 % | — |
Specification limits and source-record results are reproduced from the current product reference used by the TDS. This sample is not an issued certificate and does not identify a tested lot. Contact Alliance Chemical with the product and lot number for lot-specific documentation.
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