Fatty acids, C9-13-neo-, potassium salts

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.566 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.057 mg/L

Assessment factor:

100

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

no hazard identified

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:

PNEC oral

PNEC value:

0.02 mg/kg food

Assessment factor:

90

Additional information

The fate of fatty acids, C9 -13 neo, potassium salts in the environment is most accurately evaluated by separately assessing the fate of its constituents potassium cations and fatty acids, C9 -13 neo anions or rather its structural analogue neodecanoic acid.

 

Metal carboxylates are substances consisting of a metal cation and a carboxylic acid anion. Based on the solubility of fatty acids, C9 -13 neo, potassium salts in water, a complete dissociation resulting in potassium cations and neodecanoate anions may be assumed under environmental conditions. The respective dissociation is reversible, and the ratio of the salt /dissociated ions is dependent on the metal-ligand dissociation constant of the salt, the composition of the solution and its pH. A metal-ligand complexation constant of fatty acids, C9 -13 neo, potassium salts could not be identified. Data for alkaline earth metals appear to be generally limited. However, alkaline earth metals tend to form complexes with ionic character as a result of their low electronegativity. Further, the ionic bonding of alkaline earth metals is typically described as resulting from electrostatic attractive forces between opposite charges, which increase with decreasing separation distance between ions.Thus, it may reasonably be assumed that the behaviour of the dissociated potassium cations and neodecanoate anions in the environment determine the fate of fatty acids, C9 -13 neo, potassium salts upon dissolution with regard to (bio)degradation, bioaccumulation, partitioning resulting in a different relative distribution in environmental compartments (water, air, sediment and soil) and subsequently its ecotoxicological potential. Thus, in the assessment of environmental fate and toxicity of fatty acids, C9 -13 neo, potassium salts, read-across to the assessment entities neodecanoate and soluble potassium substances is applied since the individual ions of fatty acids, C9 -13 neo, potassium salts determine its environmental fate. Since potassium ions and neodecanoate ions behave differently in the environment, regarding their fate and toxicity, a separate assessment of each assessment entity is performed. Please refer to the data as submitted for each individual assessment entity.

For a documentation and justification of that approach, please refer to the separate document attached to section 13, namely Read Across Assessment Report for fatty acids, C9 -13 neo, potassium salts.

Conclusion on classification

Aquatic toxicity studies with fatty acids, C9 -13 neo, potassium salts are not available, thus aquatic toxicity is addressed with existing data on the dissociation products. Fatty acids, C9 -13 neo, potassium salts dissolves and dissociates into potassium and fatty acids, C9 -13 neo ions upon contact with an aqueous medium whereas the latter is represented by its strutural analogue neodecanoic acid. Potassium is naturally ubiquitous in the environment and essential for living organisms with a very low potential for toxicity to freshwater and saltwater organisms. Adverse effects are lacking up to and including the respective OECD/EC guidelines limit concentrations. The aquatic hazard assessment is therefore based on the most toxic moiety, i.e. neodecanoic acid, and respective effect concentrations are recalculated for fatty acids, C9 -13 neo, potassium salts based on the maximum fatty acid content of 84.5 %. Please refer to the section for the respective assessment entity.

 Acute (short-term) toxicity data:

As an essential element for living organisms, potassium has a very low potential for acute toxicity to freshwater as well as saltwater organisms. Regarding aquatic toxicity data for neodecanoic acid, data are available from GLP-conform guideline studies for three trophic levels: algae, invertebrates and fish. In sum, reported L(E)C50 values of potassium and neodecanoate are well above 100 mg/L and corresponding OECD test limits. Therefore, fatty acids, C9 -13 neo, potassium salts does not meet classification criteria as short-term hazard to the aquatic environment under Regulation (EC) No 1272/2008 and its subsequent adaptations.

Long-term (chronic) toxicity:

As essential element for living organisms, potassium has a very low potential for acute toxicity to freshwater as well as saltwater organisms. Reported L(E)C50 values of potassium for three trophic levels: algae, invertebrates and fish are well above 100 mg/L and corresponding OECD test limits. A similar lack of a toxic potential may be assumed long-term. Regarding the aquatic toxicity of neodecanoic acid, reliable data are available for invertebrates and fish and QSAR-based estimates for daphnids and fish. The respective NOEC/EC10 values are > 1 mg/L. Regarding algae, an EC10 or NOEC is not available for neodecanoate. However, based on the fact that the EC50 for growth rate of algae is > 100 mg/L, we may assume that it is unlikely that the EC10/NOEC < 1 mg/L. According to the QSAR-based outcome of the model ECOSAR v.2.0, neodecanoic acid has a very low potential for chronic toxicity to green algae since the chronic value (ChV = 10^([log (LOEC x NOEC)]/2)) of 12.3 mg/L is >> 1 mg/L. Thus, chronic aquatic toxicity of fatty acids, C9 -13 neo, potassium salts to algae, daphnia and fish is not expected below 1 mg/L.

Based on the surrogate approach (Table 4.1.0 (b) (iii)) of Regulation (EC) No 1272/2008, fatty acids, C9 -13 neo, potassium salts would also not meet chronic classification criteria since the EC50 for algae > 100 mg/L. Therefore, fatty acids, C9 -13 neo, potassium salts does not meet classification criteria as long-term hazard to the aquatic environment under Regulation (EC) No 1272/2008.

In sum, based on read-across of toxicity data available for potassium and neodecanoic acid, fatty acids, C9 -13 neo, potassium salts does not meet aquatic hazard criteria of Regulation (EC) No 1272/2008.