Reference information:
American Society for Testing and Materials (ASTM)
Standard Specifications for Reagent Water (Types I-IV; @ 25C)
| ASTM Type | I | II | III | IV |
| @25C | ||||
| Conductivity (microS/cm) |
0.056 | 1 | 0.25 | 5.0 |
| Resistivity (megaohms-cm) |
18 | 1 | 4 | 0.2 |
| Total Silica ( micrograms/L) |
3 | 3 | 500 | no limit |
| Total Organic Carbon (TOC) (micrograms/L) |
50 | 50 | 200 | no limit |
| Chlorides (micrograms/L) | 1 | 5 | 10 | 50 |
| Sodium (micrograms/L) | 1 | 5 | 10 | 50 |
| pH | - | - | - | 5-8 |