Fatty acids, vegetable-oil, esters with dipropylene glycol

Endpoint summary

Additional information

There are no data available investigating the short-term toxicity of Fatty acids, vegetable-oil, esters with dipropylene glycol (CAS 95009-41-9) to fish. In order to fulfil the standard information requirements, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across from a structurally related substance 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.

Decanoic acid, mixed diesters with octanoic acid and propylene glycol (CAS 68583-51-7) was chosen as a suitable read-across substance to cover the short-term toxicity to fish. The source substance is characterized as an ester of propylene glycol and fatty acids with chain lengths of C8-10. In contrast the target substance is structurally very similar defined by dipropylene glycol esterified with fatty acids of C8-10. The difference in composition of both substances is the alcohol (propylene glycol compared to dipropylene glycol). However, this difference in composition is not anticipated to be of concern to predict the toxicity of the target substance from available data of the source substance. Data from OECD SIDS indicate a low toxicity for propylene- as well as for dipropylene glycol (OECD, 2001). A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

All available experimental data on the source and target substance were performed according to internationally accepted guidelines and indicate no evidence of acute and chronic toxicity to aquatic organisms. Data for all three trophic levels are available. 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 <0.01 mg/L at 20 °C, pH=5.82 - 5.92.

The short-term toxicity to fish was determined in a standard OECD guideline study according to OECD 203 (from the source substance CAS 68583-51-7). No mortality was observed after 96 h resulting in a LL50 of > 1000 mg/L (i.e. above the water solubility limit). The same was recorded for the short-term toxicity to aquatic algae. No inhibition of growth of aquatic algae was observed in an experimental study according to OECD 201 up to the limit of water solubility.

Due to the low water solubility, long-term testing on aquatic invertebrates was considered to be necessary to assess the aquatic toxicity. The available study performed with the target substance resulted in a NOELR (21 d) ≥ 1000 mg/L indicating no effects on reproduction up to the limit of water solubility. Long-term toxicity testing to 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.

The degradation process in commercial sewage treatment plants is not suspected to be inhibited by the target substance. Available information taken from a biodegradation study with the target substance performed with activated sludge from sewage treatment plants did not indicate a risk since biodegradation was not inhibited.

Based on the results from a structurally related read-across substance (in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5) as well as reliable data from the target substance it can be concluded that Fatty acids, vegetable-oil, esters with dipropylene glycol (CAS 95009-41-9) 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 substance support the read-across by showing a consistent pattern of results.

A detailed reference list is provided in the technical dossier (see IUCLID, section 13) and within CSR.