| Composizione | Fiocco/perla 96% | Fiocco/perla 98% | Fiocco/perla 99% |
| NaOH | 96% min. | 98% min. | 99% min. |
| Na2C03 | 1% max. | 0.5% max. | 0.4% max. |
| NaCl | 2% max. | 0.03% max. | 0.015% max. |
| Fe2O3 | 0.01% max. | 0.005% max. |
0.001% max
|