2-ethylhexanoic acid, manganese salt

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.065 mg/L

PNEC freshwater (intermittent releases):

0.155 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.002 mg/L

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

47.55 mg/L

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

7.26 mg/kg sediment dw

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.73 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:

1.24 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, manganese salt (CAS: 15956-58-8), a read-across approach from data for the metal cation (manganese) and the organic anion (2-ethylhexanoate) is followed. This read-across strategy is based upon the observation that upon dissolution in aqueous media, 2-ethylhexanoic acid, manganese salt completely dissociates and only is present in its dissociated form, i.e. as manganese cation and 2-ethylhexanoate anion. Data on the environmental fate, ecotoxicity and toxicity for both transformation products (manganese cation and 2-ethylhexanoate anion) together can therefore be combined in an additive approach to predict the corresponding properties of 2-ethylhexanoic acid, manganese 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, manganese salt into the manganese 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 manganese cation and 2-ethyl hexanoate 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 2-ethylhexanoic acid, manganese 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 manganese cation and 2-ethyl hexanoate anion is preferred. The dose additivity approach is used to explain the ecotoxicological effects of 2-ethylhexanoic acid, manganese salt based on the data for the individual transformation products (manganese cation and 2-ethylhexanoate anion).

Conclusion on classification

No reliable ecotoxicological data are available for 2-ethylhexanoic acid, manganese salt. The substance will dissociate into manganese and 2-ethyl hexanoate ions after dissolution in water and hence can be regarded as a mixture of both constituent ions. In the absence of toxicity data for 2-ethylhexanoic acid, manganese salt, its classification for environmental hazards is therefore based on the classification of the transformation products (manganese and 2-ethylhexanoate ions).

The manganese ions are classified as Aquatic Chronic 2. The organic moiety, i.e. 2-ethyl hexanoic acid, is not classified as hazardous to the aquatic environment. Taking into account the weight of manganese in 2-ethylhexanoic acid, manganese salt or manganese bis(2-ethylhexanoate) (up to 16.8%), the summation method results in an Aquatic Chronic 2 classification for 2-ethylhexanoic acid, manganese salt.

It is concluded that an Aquatic Chronic 2 classification for hazards to the aquatic environment is appropriate for 2-ethylhexanoic acid, manganese salt.