Fatty acids, soya, 2-ethylhexyl esters

Endpoint summary

Additional information

Data investigating the aquatic toxicity of Fatty acids, soya, 2-ethylhexyl esters (CAS 93572-14-6) are not available. In order to fulfil the standard information requirements set out in Annex VII, 8.5, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across from structurally related substances was conducted. In accordance with Article 13 (1) of Regulation (EC) No 1907/2006, "information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI are met.” In particular for aquatic toxicity, information shall be generated whenever possible by means other than vertebrate animal tests, which includes the use of information from structurally related substances (grouping or read-across).
The general rules for grouping of substances and read-across approach laid down in Annex XI, Item 1.5, of Regulation (EC) No 1907/2006 state that substances may be predicted as similar provided that their physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity.
The target substance and source substances show structural similarities and are characterised by similar physio-chemical properties. The target substance and source substances are monoesters of primary and secondary (isopropanol) alcohols C2-C8 and fatty acids (saturated and unsaturated) with the chain length C8-C18. A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).
Experimental data for the target substance Fatty acids, soya, 2-ethylhexyl esters (CAS 93572-14-6) are not available. Therefore, the source substances Fatty acids, C8-16, 2-ethylhexyl esters (CAS 135800-37-2) and 2-ethylhexyl oleate (CAS 26399-02-0) and Fatty acids, C16-18 and C18-unsatd., 2-ethylhexyl esters (CAS 85049-37-2) were selected to cover the aquatic toxicity endpoints.
In accordance with Regulation (EC) No 1907/2006, Annex XI, 1.5, grouping and read-across, the target substance and all source substances are not considered to be harmful to aquatic organisms based on the results from short-term studies with fish, aquatic invertebrates and aquatic algae. Moreover, long-term studies with aquatic invertebrates did not result in any long-term effects on reproduction. The available short-term toxicity studies (fish, Daphnia, algae) did not demonstrate any toxicity of the analogue substances to aquatic organisms up to the limit of water solubility.
The assessment of the acute toxicity of the target substance Fatty acids, soya, 2-ethylhexyl esters (CAS 93572-14-6) to fish is based on a read across the structurally most similar analogue source substances Fatty acids, C16-18 and C18-unsatd., 2-ethylhexyl esters (CAS 85049-37-2) and Fatty acids, C8-16, 2-ethylhexyl esters (CAS 135800-37-2). Mortality or symptoms of intoxication of fish were not observed and thus a LC50 (96h) > 10000 mg/L based on the nominal substance concentration was reported in both read across studies.
The assessment of the acute toxicity of Fatty acids, soya, 2-ethylhexyl esters (CAS 93572-14-6) to aquatic invertebrates is therefore based on a read across the structurally analogue source substances 2-ethylhexyl oleate (CAS 26399-02-0) and Fatty acids, C8-16, 2-ethylhexyl esters (CAS 135800-37-2). Both studies determined no effect up to the limit of water solubility of the test substances and an EC50 (48h) > 100 mg/L was reported.
Short-term toxicity to aquatic algae: The assessment of the acute toxicity of Fatty acids, soya, 2-ethylhexyl esters (CAS 93572-14-6) is based on a read across the structurally similar analogue source substances 2-ethylhexyl oleate (CAS 26399-02-0) and Fatty acids, C8-16, 2-ethylhexyl esters (CAS 135800-37-2) . Both studies were conducted with Scenedesmus subspicatus and reported no toxicological effects on aquatic algae up to the limit of water solubility of the substances and an ErC50(72 h) of > 100 mg/L was determined. 
Data on the long-term toxicity to fish are not available for any of the analogue substances. However, short-term studies available for fish, daphnia and algae, all indicate a low potential for aquatic toxicity. Moreover, the reliable NOECs obtained from twoa daphnia reproduction studies are above the limit of water solubility. Additionally, the aquatic concentrations of the target and source substances are expected to be very low. This assumption is based primarily on the lack of water solubility, the ready biodegradability and high adsorption potential (log Koc > 3, MCI method, KOCWIN v2.00). The substances are thus expected to be eliminated in sewage treatment plants to a high extent. In the aquatic environment, the concentration in the water phase will be reduced by biodegradation and adsorption to solid particles and to sediment. If exposure would occur, food ingestion is likely to be the main uptake route of the analogue substances in fish, since the substances will be adsorbed to solid particles potentially ingested by fish. In the case of ingestion, the analogue substances are predicted to undergo metabolism. Studies on rats demonstrated that esters of primary alcohols, containing from 1 to 18 carbon atoms, with fatty acids, containing from 2 to 18 carbon atoms, are hydrolysed by pancreatic lipases. Measured rates of enzyme catalysed hydrolysis varied between 2 and 5 µeq/min/mg enzyme for the different chain lengths (Mattson and Volpenhein, 1972; and references therein). The esters are thus expected to be hydrolysed by lipases. The resulting free fatty acids and alcohols are absorbed from the intestine into the blood stream. The alcohols are metabolised primarily in the liver through a series of oxidative steps, finally yielding carbon dioxide (Berg et al., 2001; HSDB). Fatty acids are either metabolised via the beta-oxidation pathway in order to generate energy for the cell or reconstituted into glyceride esters and stored in the fat depots in the body (Berg et al., 2001). Metabolic pathways in fish are generally similar to those in mammals. Lipids and their constituents, fatty acids, are in particularly a major organic constituent of fish and play major roles as sources of metabolic energy (Tocher, 2003).
In conclusion, the analogue substances will be mainly taken up by ingestion and digested through common metabolic pathways, providing a valuable energy source for the organism, as dietary fats. Long-term toxic effects on fish are therefore not to be expected.
The assessment of long-term toxicity of Fatty acids, soya, 2-ethylhexyl esters (CAS 93572-14-6) to aquatic invertebrates is based on a study conducted with the analogue substances 2-ethylhexyl oleate (CAS 26399-02-0) and Fatty acids, C8-16, 2-ethylhexyl esters (CAS 135800-37-2). The studies reported no effect of the test substances on the reproduction or mortality of the test organisms. Therefore, a NOEC(21 d) > 1 mg/L (nominal) based on reproduction was determined in both studies.
The assessment of the toxicity of Fatty acids, soya, 2-ethylhexyl esters (CAS 93572-14-6) is based on a read across to the analogue substance Fatty acids, C16-18 and C18-unsatd., 2-ethylhexyl esters (CAS 85049-37-2). The test substance did not affect the respiration rate and thus an EC50(3h) value of >100 mg/L was determined.
Overall, it can be concluded that the target substance Fatty acids, soya, 2-ethylhexyl esters (CAS 93572-14-6) is not toxic to aquatic organisms up to the limit of water solubility, based on the results from a suitable source substance.