Nickel bis(2-ethylhexanoate)

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.033 mg/L

PNEC freshwater (intermittent releases):

1.16 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.021 mg/L

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

1.62 mg/L

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

7.27 mg/kg sediment dw

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.74 mg/kg sediment dw

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

1.22 mg/kg soil dw

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

PNEC oral

PNEC value:

0.6 mg/kg food

Additional information

Read-across approach

In the assessment of the environmental fate, ecotoxicity and toxicity of nickel bis(2-ethylhexanoate) (CAS: 4454-16-4), a read-across approach from data for the metal cation (nickel) and the organic anion (2-ethylhexanoate) is followed. This read-across strategy is based on the observation that upon dissolution in aqueous media, metal carboxylate salts completely dissociate and only are present in their dissociated form, i.e. as metal cation and carboxylate anion. Data on the environmental fate, ecotoxicity and toxicity for both transformation products of nickel bis(2-ethylhexanoate) (i.e., nickel cation and 2-ethylhexanoate anion) together can therefore be combined in an additive approach to predict the corresponding properties of nickel bis(2-ethylhexanoate).

A detailed justification for the read-across approach is added as a separate document in section 13 of IUCLID.

Upon dissolution and dissociation of nickel bis(2-ethylhexanoate) into the nickel cation and 2-ethylhexanoate anion, both ions will each show the proper (bio)degradation, bioaccumulation and partitioning behaviour in the environment, as reported for the corresponding ion. The environmental fate and behaviour for the nickel cation and 2-ethylhexanoate anion is predicted to be clearly different from each other, resulting in a different relative distribution over the environmental compartments (water, air, sediment and soil). Because the relative exposure to both constituent ions is hence predicted to be different from the original composition of nickel bis(2-ethylhexanoate), data for the ecotoxicological properties of this substance tested as such are considered less relevant for its effects and risk assessment and a read-across approach from data for both the nickel cation and 2-ethylhexanoate anion is preferred. The dose additivity approach is used to explain the ecotoxicological effects of nickel bis(2-ethylhexanoate) based on the data for the individual transformation products (nickel cation and 2-ethylhexanoate anion).

Conclusion on classification

Nickel 2 -ethylhexanoate is legally classified as Aquatic acute and chronic 1 for aquatic toxicity according to the first ATP of the CLP Regulation.