| Meets A.C.S. Specifications |
| Meets Reagent Specifications for testing USP/NF monographs |
| Assay (Na2S2O3·5H2O) (by iodometry) | 99.5 - 101.0 % |
| Insoluble Matter | max. 0.005 % |
| pH of 5% Solution at 25°C | 6.0 - 8.4 |
| Nitrogen Compounds (as N) | max. 0.002 % |
| Sulfate and Sulfite (as SO4) | max. 0.1 % |
| Sulfide (S) | Passes Test |
| For Laboratory, Research or Manufacturing Use |