2,2-bis(hydroxymethyl)propane-1,3-diyl didocosanoate

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 2,2-bis(hydroxymethyl)propane-1,3-diyl didocosanoate (CAS 68258-72-0).
The target substance 2,2-bis(hydroxymethyl)propane-1,3-diyl didocosanoate (CAS 68258-72-0) is characterized di-, tri-, tetraester of pentaerythritol an fatty acids with a chain lengths of C22. The degree of esterification is variable. However, mainly tri- and tetraesters are the result of the esterification process. Source substance Fatty acids, lanolin, esters with pentaerythritol (CAS 68440-09-5) is a pentaerythritol tetraester of long-chain linear and iso-branched fatty acids (even and odd) up to C29. Moreover, a small amount of hydroxylated fatty acids of C16 is present. Source substance Fatty acids, C16-18 and C18-unsatd., esters with pentaerythritol (CAS 85711-45-1) is a mono-, di-, tri- and/or tetraester (in a variable composition) of mainly C16 and C18 (saturated and unsaturated) up to C22 fatty acids. Source substance Fatty acids, C16-18 and C18-unsatd., tetraesters with pentaerythritol (CAS 68604-44-4) is characterised as a tetraester of pentaerythritol with mainly C18 unsaturated fatty acids.
The target substance and the selected source substances do not share common functional groups (structural alerts) which might change the overall aquatic toxicity. They are all esters of pentaerythritol esterified with linear and branched as well as saturated and unsaturated fatty acids and thus their environmental toxicity and fate is considered to be comparable.
A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

All experimental studies available for suitable source substances 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 two standard OECD guideline studies according to OECD 203 (with source substances CAS 68440-09-5 + CAS 85711-45-1). No mortality was observed after 96 h resulting in a LL50 (96 h) > 100 mg/L (i.e. above the water solubility limit). The short-term toxicity to aquatic invertebrates and to aquatic algae was determined for suitable source substances (CAS 68440-09-5 + CAS 68604-44-4). 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.

Due to the very low water solubility of the target substance chronic testing was considered necessary for the assessment of aquatic toxicity. A chronic study with a suitable source substance (CAS 85711-45-1) did not result in toxic effects on reproduction of Daphnia magna up to the water solubility limit (NOELR (21 d) ≥ 1 mg/L). In combination with the acute results, effects on aquatic organisms are not to be expected and chronic fish testing was not proposed.

Inhibition of the degradation process in conventional sewage treatment plants by the target substance is not expected. Experimental data on the target substance and a suitable source substance do not indicate inhibition of degradation in a standard biodegradation study.

Based on the result from available studies on structurally related read-across substances (in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5) it can be concluded that the target substance 2,2-bis(hydroxymethyl)propane-1,3-diyl didocosanoate (CAS 68258-72-0) 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.