来源于欧洲EN ISO 3696-1995。
| Parameter | Grade1 | Grade2 | Grade3 | |
| pH value at 25 °C inclusive range | Not applicable | Not applicable | 5.0 to 7.5 | |
| Electrical conductivity, mS/m at 25℃, max. | 0.01 | 0.1 | 0.5 | |
| Oxidizable matter Oxygen(O) content mg/l, max | Not applicable | 0.08 | 0.4 | |
| Absorbance at 254nm and 1cm optical pathlength, absorbance units, max. | 0.001 | 0.01 | Not specified | |
| Residue after evaporation on heating at 110℃,mg/kg, max. | Not applicable | 1 | 2 | |
| Silica(SiO2) content mg/l, max. | 0.01 | 0.02 | Not specified | |
