Reaction products from the esterification of neopentylglycol with fatty acids, C16-18 (even numbered) and C18-unsatd. and fatty acids, C18-unsaturated, dimers

Endpoint summary

Additional information

The dataset investigating the aquatic toxicity of Reaction products from the esterification of neopentylglycol with fatty acids, C16-18 (even numbered) and C18-unsatd. and fatty acids, C18-unsaturated, dimers 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 source substances neopentylglycol dioleate (CAS 42222-50-4) and Heptanoic acid, ester with 2,2-dimethyl-1,3-propanediol (CAS 68855-18-5) are considered to be similar on the basis of the structural similar properties and/or activities. The available endpoint information on the source substances is used to predict the aquatic toxicity of the target substance Reaction products from the esterification of neopentylglycol with fatty acids, C16-18 (even numbered) and C18-unsatd. and fatty acids, C18-unsaturated, dimers.

The target substance is characterized as a diester of neopentylglycol esterified with mainly C18 unsaturated fatty acids. The main constituent of the source substance neopentylglycol dioleate (CAS 42222-50-4) is neopentyl glycol dioleate containing additional constituents of higher molecular weight. Heptanoic acid, ester with 2,2-dimethyl-1,3-propanediol (CAS 68855-18-5) consists of neopentylglycol diesterified with heptanoic acid (mono-constituent substance). All selected source substances are representative for the target substance. Neopentylglycol dioleate (CAS 42222-50-4) is the most suitable substance as it is a constituent of the target substance. None of the selected source substances contains any functional group which might change the overall mode of action and toxicity. A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

Experimental studies according to standard guidelines investigating the acute toxicity to aquatic invertebrates and the toxicity to aquatic algae are available for the target substance. No effects up to the water solubility limit were observed in both studies. For the other necessary endpoints experimental data from the suitable source substances indicate no evidence of acute toxicity to fish and chronic toxicity to aquatic invertebrates. Long-term toxicity testing on fish was not considered to be necessary since there was no evidence from the available data that fish are more sensitive compared to aquatic invertebrates. No toxicity to fish was observed in the available acute tests. Thus, in order to avoid unnecessary vertebrate testing, no long-term testing with fish was proposed. In summary, 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. The degradation process in commercial sewage treatment plants is not suspected to be inhibited by the target substance. One available study performed with activated sludge from a sewage treatment plant did not indicate a risk since respiration of activated sludge microorganisms was not inhibited. 

Based on the result from structurally related source substances (in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5) it can be concluded that Reaction products from the esterification of neopentylglycol with fatty acids, C16-18 (even numbered) and C18-unsatd. and fatty acids, C18-unsaturated, dimers exhibits no toxic effects on freshwater organisms up to the limit of the water solubility. As it can be seen in the data matrix of the analogue justification in IUCLID Section 13, all reliable data from the target and the source substances support the read-across by showing a consistent pattern of results.