| Items | Tech Grade | Food Grade |
| Na2S2O5 content | 97.0 %min | 97.0 %min |
| SO2 | 65.0%min | 65.0%min |
| Heavy metals (as Pb) | 0.0005%max | |
| Arsenic (As) | 0.0001%max | 0.0001%max |
| Iron (Fe) | 0.005%max | 0.003%max |
| Water insoluble | 0.05%max | 0.04%max |
| Items | Tech Grade | Food Grade |
| Na2S2O5 content | 97.0 %min | 97.0 %min |
| SO2 | 65.0%min | 65.0%min |
| Heavy metals (as Pb) | 0.0005%max | |
| Arsenic (As) | 0.0001%max | 0.0001%max |
| Iron (Fe) | 0.005%max | 0.003%max |
| Water insoluble | 0.05%max | 0.04%max |