Registration Dossier
Registration Dossier
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EC number: 231-970-5 | CAS number: 7782-91-4
Ecotoxicological Summary
Administrative data
Hazard for aquatic organisms
Hazard for air
Hazard for terrestrial organisms
Hazard for predators
Additional information
Read-across approach
There are no ecotoxicological data available for Molybdic acid. In the assessment of the ecotoxicity of Molybdic acid, read-across from data for the molybdate ion is used. This read-across strategy is based upon the assumption that upon release to the environment and dissolution in aqueous media, Molybdic acid will dissociate and only be present in its dissociated form, i.e. as molybdate and hydrogen ions.
For most metal-containing compounds, it is the potentially bioavailable metal ion that is liberated (in greater or lesser amounts) upon contact with water that is the moiety of ecotoxicological concern. The solubility of Molybdic acid in water is 675.5 mg substance/L and is above the range of effects concentrations for dissolved molybdenum in the aquatic environment (lowest acute and chronic effect values for freshwater organisms: LC50 of 131 mg Mo/L and EC10 of 43.2 mg Mo/L, respectively). Therefore ecotoxicity data for soluble molybdenum salts can be directly used in a read-across approach for Molybdic acid.
Acute toxicity data for Molybdate ion (only most sensitive species per trophic level):
| Trophic level | Endpoint | Value |
| Fish | 96-h LC50 |
609 mg Mo/L (Pimephales promelas) |
| Aquatic invertebrates | 48 -h EC50 | 131 mg Mo/L (Daphnia magna) |
| Algae | 72 -h ErC50 | 333 mg Mo/L (Pseudokirchneriella subcapitata) |
Conclusion on classification
Molybdic acid will dissociate into molybdate and hydrogen ions after dissolution in water and hence can be regarded as a mixture of both constituent ions. In the absence of toxicity data for Molybdic acid, its classification for environmental hazards is based on the classification of molybdate ion. Molybdate ion is not classified as hazardous to the aquatic environment. Therefore, it is concluded that Molybdic acid is not classified as hazardous to the aquatic environment.
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