Fatty acids, C18-unsatd, dimers, hydrogenated, diisopropyl esters

Endpoint summary

Additional information

The experimental dataset for Annex VIII is not complete. In order to fulfil the standard information requirements, 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).

Having regard to 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 whereby 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 all source substances are considered to be similar on the basis of the structural similar properties and/or activities. The available endpoint information on the source substance is used to predict comparable results for the target substance Fatty acids, C18-unsatd., dimers, hydrogenated diisopropyl esters (CAS 103213-20-3).
The target substance Fatty acids, C18-unsatd., dimers, hydrogenated diisopropyl esters (CAS 103213-20-3) is characterized by two/three dimerised fatty acid moieties (C18 unsaturated) esterified with the alcohol component isopropanol. The source substance Fatty acids, C18-unsatd., dimers, 2-ethylhexyl esters (CAS 68334-05-4) is characterized as a dimerised ester of two C18:1 fatty acids with 2-ethylhexanol.

A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

All available experimental studies for the target substance itself and a suitable source substance were performed according to internationally accepted guidelines. They cover all three trophic levels of an aquatic ecosystem. No toxicity was observed up to the limit of water solubility in all available experimental studies. The water solubility of the target substance was determined to be < 0.05 mg/L at 20 °C, pH = 6.3 - 6.7.

The short-term toxicity to fish was determined in a standard OECD guideline study according to OECD 203 (on the target substance itself). No mortality was observed after 96 h resulting in a LL50 > 10000 mg/L (i.e. above the water solubility limit). The short-term toxicity to aquatic invertebrates and to aquatic algae was determined for a suitable source substance (CAS 68334-05-4). No immobilization of Daphnia magna and no inhibition of growth of aquatic algae were observed in experimental studies according to OECD guidelines up to the limit of water solubility.

Chronic testing was considered not necessary for the assessment of aquatic toxicity since effects on aquatic organisms of three different trophic levels were not observed. Moreover, in order to avoid unnecessary vertebrate testing, no long-term testing with fish was proposed.

Inhibition of the degradation process in commercial sewage treatment plants by the target substance is not expected. An experimental study with Pseudomonas putida demonstrated no effects on bacterial growth up to a concentration of 10000 mg/L (ISO 10712).

Based on the result from available studies on the target substance and a structurally related read-across substance (in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5) it can be concluded that the target substance Fatty acids, C18-unsatd., dimers, hydrogenated diisopropyl esters has no toxic effects on freshwater organisms up to the limit of the water solubility. The data matrix of the analogue justification in IUCLID Section 13 shows that all reliable data from the source substances support the read-across by a consistent pattern of results.