2-ethylhexanoic acid, zirconium salt

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.47 mg/L

PNEC freshwater (intermittent releases):

1.3 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.047 mg/L

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

93.1 mg/L

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

8.27 mg/kg sediment dw

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.827 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:

1.38 mg/kg soil dw

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

Read-across approach

In the assessment of the environmental fate, ecotoxicity and toxicity of 2-ethylhexanoic acid, zirconium salt (CAS: 22464-99-9), a read-across approach from data for the metal (zirconium) and the organic anion (2-ethylhexanoate) is followed. This read-across strategy is based on the observation that upon dissolution in aqueous media, 2-ethylhexanoic acid, zirconium salt completely dissociates and only is present in its dissociated form, i.e., as zirconium and 2-ethylhexanoate ions. Data on the environmental fate, ecotoxicity and toxicity for both transformation products (zirconium and 2-ethylhexanoate) together can therefore be combined in an additive approach to predict the corresponding properties of 2-ethylhexanoic acid, zirconium salt.

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

Upon dissolution and dissociation of 2-ethylhexanoic acid, zirconium salt into zirconium and 2-ethylhexanoate, 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 zirconium and 2-ethylhexanoate 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 in the different environmental compartments is hence predicted to be different from the original composition of 2-ethylhexanoic acid, zirconium salt, 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 zirconium and 2-ethylhexanoate ions is preferred. The dose additivity approach is used to predict the ecotoxicological effects of 2-ethylhexanoic acid, zirconium salt based on the data for the individual transformation products (zirconium and 2-ethylhexanoate ions).

Conclusion on classification

The classification of 2-ethylhexanoic acid, zirconium salt for environmental hazards is based on a weight of evidence approach, taking into account the data for 2-ethylhexanoic acid, zirconium salt itself and the classification of its moieties (zirconium and 2-ethyl hexanoic acid).

• Data are available for the acute effects of 2-ethylhexanoic acid, zirconium salt on the immobilisation of Daphnia magna, showing no effect at the largest dose tested (100 mg/L). The EC50 of >100 mg/L does not results in the need for a classification of 2-ethylhexanoic acid, zirconium salt as hazardous to the aquatic environment.


• The substance 2-ethylhexanoic acid, zirconium salt will dissociate into zirconium and 2-ethylhexanoate ions after dissolution in water and hence can be regarded as a mixture of both constituent ions. The classification of 2-ethylhexanoic acid, zirconium salt for environmental hazards can therefore also based on the classification of its moieties (zirconium and 2-ethylhexanoic acid). Both zirconium and 2-ethylhexanoic acid are not classified as hazardous to the aquatic environment, and according to the summation method, 2-ethylhexanoic acid, zirconium salt is not hazardous to the aquatic environment.

 

It is therefore concluded that 2-ethylhexanoic acid, zirconium salt is not classified as hazardous to the aquatic environment.