Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
PNEC aqua (freshwater)
PNEC value:
0.29 µg/L
Assessment factor:
1 000
Extrapolation method:
assessment factor
PNEC freshwater (intermittent releases):
2.9 µg/L

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
0.029 µg/L
Assessment factor:
10 000
Extrapolation method:
assessment factor

STP

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

Sediment (freshwater)

Hazard assessment conclusion:
PNEC sediment (freshwater)
PNEC value:
4.37 mg/kg sediment dw
Extrapolation method:
equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:
PNEC sediment (marine water)
PNEC value:
0.44 mg/kg sediment dw
Extrapolation method:
equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:
no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
PNEC soil
PNEC value:
0.001 mg/kg soil dw
Extrapolation method:
equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential to cause toxic effects if accumulated (in higher organisms) via the food chain

Additional information

Tests have been conducted with diammonium sodium hexakis(nitrito-N)rhodate for acute Daphnia, algae and toxicity to microorganisms endpoints. As Daphnia and algal results are similar for the two substances, and as algae are the most sensitive trophic level and will drive classification, it is considered appropriate to read across data for acute toxicity to fish from another rhodium(III) substance, rhodium trinitrate (hydrate). These data are used for classification purposes.

For PNEC derivation all data for rhodium(III) substances has been pooled and the PNEC values derived based on the most sensitive result. In the risk assessment, emissions of different rhodium substances are not analysed separately and therefore measured environmental concentrations are available based on total rhodium concentrations. As the measured emissions data is not apportioned to a particular rhodium(III) substance, a single set of PNECs covering all rhodium substances in the same oxidation state is considered to be the most appropriate approach for conducting the risk assessment. For aquatic PNECs the lowest EC50 value is for the rhodium(III) substance rhodium(III) chloride. There is some indication that rhodium substances containing a chloro ligand may be more toxic than those without, and therefore using the value for rhodium trichloride as the key value for PNEC derivation for all rhodium(III) substances is likely to be worst case.

Conclusion on classification

Acute Daphnia and algae data are available for the substance itself, and acute fish data are read across from rhodium trinitrate (hydrate). The most sensitive trophic level is algae, with an ErC50 of 4.5 mg test item L-1 and an ErC10 of 0.313 mg L-1. As the EC50 value is above 1 no acute environmental classification is assigned for this substance. As the only chronic data available is an ErC10 for algae, the chronic classification is determined based on both the acute and chronic data, with the most stringent classification assigned. As this substance is not rapidly degradable, both the acute and chronic data lead to a Chronic Category 2 (H411) classification being assigned to this substance.