Glycerides, C18-36

Endpoint summary

Additional information

There are currently no data available investigating the aquatic toxicity of Dub TGI 24. 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 substances is used to predict comparable results for the target substance Dub TGI 24.

The target and the source substances cover aliphatic (fatty) acid esters of glycerol. The target substance is characterized as a mono, di and triesters with glycerol and 2-decyltetradecanoic acid. Three structurally very similar substances were selected as source substances to cover the data requirements. Glycerides,C14-18 and C16-18 unsaturated, mono-, di- and tri- (CAS 91052-28-7) is characterized as mono, di and triester of glycerol with fatty acids of C14-18 and C16-18 unsaturated. Glycerides, C16-18 and C18-unsatd. (CAS 67701-30-8) is an UVCB substance consisting of C16 – C18 (even) and C18 unsaturated fatty acids with glycerol mainly as triglycerides. Docosanoic acid, ester with 1,2,3-propanetriol (CAS 77538-19-3) could be mono, di and triester mainly with C22 fatty acid and glycerol. A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

All experimental studies available for the 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 very low with a concentration of < 0.05 mg/L at 20 °C.

The short-term toxicity to fish was determined in studies according to internationally accepted guidelines (ISO guideline 7346-1) for the source substances CAS 67701-30-8 and CAS 77538-19-3, and one national guideline (German national Guideline DIN 38412/15) for the source substance CAS 91052-28-7. No mortality was observed after 96 (48) h resulting in a LC50 > 10000 mg/L (i.e. above the water solubility limit).

The same was recorded for the short-term toxicity to aquatic invertebrates. No effects on Daphnia magna are recorded in experimental studies according to internationally accepted guidelines (OECD or EU-Method) up to the limit of water solubility.

No effects on the growth rate of Scenedesmus subspicatus was observed in filtrated solutions conducted according to internationally accepted guidelines (OECD or EU-Method). Effects in oversaturated solutions with undissolved test substance were observed, but well above the water solubility and attributed to physical impacts of the undissolved test substances and not to a systemic toxicity of the tested substances.

Long-term testing with aquatic invertebrates was conducted according to OECD 211 with the source substance Glycerides,C14-18 and C16-18 unsaturated, mono-, di- and tri- (CAS No. 91052-28-7). At the end of the exposure period (21d), no effects on survival, reproduction or any other adverse effects were reported (NOELR ≥ 10 mg/L, nominal).

Long-term toxicity testing to fish was not considered to be necessary since there was no toxicity to fish observed in the available acute tests and there was no evidence from the available data that fish are more sensitive compared to aquatic invertebrates. Long-term testing to daphnia shows no effects on survival, reproduction or any other adverse effects at the end of the exposure period (NOELR ≥ 10 mg/L, nominal). 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. A toxicity control from a biodegradation study according to OECD 301F did not indicate any inhibition of biodegradation up to a concentration of 100 mg/L and the substance was readily biodegradable.

Based on the results from structurally related source substances (in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5) it can be concluded that the target substance Dub TGI 24 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 source substances support the read-across by showing a consistent pattern of results.