Table 1: EU classification for fish toxicity.
| Class | LC50 | Damage |
| 1 | < 1 mg/L | Very toxic to aquatic organisms |
| 2 | 1 - 10 mg/L | Toxic to aquatic organisms |
| 3 | 10 - 100 mg/L | Harmful to aquatic organisms |
| 4 | > 100 mg/L | May cause long term adverse effects to aquatic organisms |