Oleic acid, copper salt

Endpoint summary

Description of key information

Aquatic toxicity data of oleic acid, copper salt are not available. Thus, read-across to the assessment entities soluble copper substances and oleic acid is applied since the ions of oleic acid, copper salt determine its fate and toxicity in the environment. Reliable studies indicate that the moiety of ecotoxicological concern are copper cations.

Copper:

A large set of reliable aquatic toxicity data on copper ions is available from multiple studies covering all relevant trophic levels. The lowest acute and chronic Ecotoxicity Reference Values (ERVs) derived for copper at different pH bands amount to 12 µg Cu/L (acute, pH 6) and 12 µg Cu/L (chronic, pH 7). Please refer to the respective section of the assessment entity and to attached reports for further information on acute and chronic aquatic toxicity of copper:

"The environmental hazard classification of copper, Version 1.1 (European Copper Institute, 2018)"

"Derivation of acute ERVs for copper, (European Copper Institute, 2016)"

"Derivation of chronic Ecotoxicity Reference Values (ERVs) for copper, updated version (European Copper Institute, 2018)"

 

The potential of copper for toxicity to microorganisms is based on a weight-of-evidence approach of five studies, resulting in a 30-d NOEC of 0.23 mg dissolved Cu/L (inhibition of total respiration / respiration rate) for microorganisms. 

 

Oleic acid:

Oleic acid (i.e. C18- fatty acid) is expected to be non-toxic to aquatic invertebrates and algae up to and including its water solubility limit. Fatty acids as contained in plant and animal tissue are a natural component of the environment, represent a significant part of the normal daily diet and are rapidly degraded and therefore not expected to accumulate in the environment. Therefore, short- and long-term aquatic toxicity of oleic acid is considered to be low.

 

Oleic acid, copper salt:

Based on the fact that oleic acid is assumed to have a very low potential for aquatic toxicity and that acute and chronic ERV for copper amount to 12.1 µg Cu/L (acute, pH 6) and 12 µg Cu/L (chronic, pH 7), the aquatic hazard assessment is conservatively based on copper ions as the moiety of ecotoxicological concern. Therefore, existing ERVs of copper are recalculated for oleic acid, copper salt based on the maximum copper content of

oleic acid, copper salt of 13.1 % resulting in :

- an acute ERV (oleic acid, copper salt) of 92.4 µg/L, and a

- chronic ERV (oleic acid, copper salt) of 91.6 µg/L.

The toxic potential of oleic acid, copper salt to microorganisms is estimated with 1.76 mg/L based on a maximum copper content of oleic acid, copper salt of 13.1 % and the 30-d NOEC of 0.23 mg dissolved Cu/L.