| Primo grado | Secondo grado | |
| Ni | 34%min | 32%min |
| Cu | 0.01% max | 0.01% max |
| Fe | 0.01% max | 0.02% max |
| Zn | 0.05% max | 0.05% max |
| SO4 | 0.5% max | 0.5% max |
| Cl- | 0.05% max | 0.05% max |
| Acqua Insol materia | 0.4% max | 0.5% max |