Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
no hazard identified

Marine water

Hazard assessment conclusion:
no hazard identified

STP

Hazard assessment conclusion:
PNEC STP
PNEC value:
200 mg/L
Assessment factor:
10
Extrapolation method:
assessment factor

Sediment (freshwater)

Hazard assessment conclusion:
no hazard identified

Sediment (marine water)

Hazard assessment conclusion:
no hazard identified

Hazard for air

Air

Hazard assessment conclusion:
no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
no hazard identified

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

Conclusion on classification

The water solubility of ditantalum pentaoxide determined according to OECD Guideline 105 is < 5 µg/L at 10 °C and 20 °C (Wenighöfer & Fröschl, 2012). The available key studies addressing three different aquatic species (daphnia, algae and fish) were conducted with nominal test substance concentrations of 1 mg/L. Actual (dissolved) test substance concentrations were not analytically verified. However, due to the reported procedures for the preparation of test solutions, the test substance is considered to have been tested at its maximum solubility in the respective test media. The following results based on the nominal test substance concentration were obtained: 

- Short term toxicity to fish (Brachydanio rerio): 96 hour LC0 1 mg/L (limit of solubility) (Caspers, 2001).

- Short-term toxicity testing to invertebrates (Daphnia magna): 48 hour EC0 1 mg/L (limit of solubility). (Müller, 2001)

- Growth inhibition study on aquatic plants (Desmodesmus subspicatus): no toxic effects were observed at 1 mg/L (limit of solubility). (Casper, 2000)

The assessment of ready biodegradability is not applicable to inorganic substances.

Based on the high insolubility of the substance in water and its high molecular weight, it is not expected to bioaccumulate.

With respect to the information available for this substance (presented above), the substance is not classified as hazardous to the aquatic environment (short or long-term) in accordance with Regulation (EC) 1272/2008.