Bis(16-methylheptadecyl) malate

Endpoint summary

Additional information

Data investigating the aquatic toxicity of Diisooctadecyl malate (CAS 67763-18-2) are not available. In accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across to the structurally related substances bis(C12-C13)alkyl-2-hydroxybutandioate (CAS 149144-85-4) and Diisodecyl Azelate (CAS 28472-97-1) was conducted to fulfil the standard information requirements. 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). According to Annex XI, Item 1.5, of Regulation (EC) No 1907/2006 substances can be considered similar if 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 Diisooctadecyl malate is an UVCB dicarboxylic ester, derived from isooctadecanol and malic acid. The source substances are diesters derived from similar or structurally related dicarboxylic acids, namely malic (C4) and azelaic (C9) acid. The parent alcohol of these diesters generally falls in the C10-C18 carbon number range, including linear and branched alcohols.The target substance and the source substances are characterised by a low water solubility, low vapour pressure and high log Koc. Thus, all substances are expected to have a similar environmental fate and ecotoxicity profile. The available studies indicate that the source substances are not toxic to aquatic organisms up to the limit of water solubility.

In accordance with Regulation (EC) No 1907/2006, Annex XI, 1.5, grouping and read-across, Diisooctadecyl malate (CAS 67763-18-2) is not considered to be harmful to aquatic organisms based on the results of the available read across studies conducted with fish, aquatic invertebrates and algae.

Experimental data on the acute toxicity of the read-across substance bis(C12-C13)alkyl-2-hydroxybutandioate (CAS 149144-85-4) are available for aquatic invertebrates and algae. The short-term toxicity of Diisodecyl Azelate (CAS 28472-97-1) was assessed in a guideline study according to OECD guideline 203 (Hansonis-Jouleh, 1993). This study was conducted with the fish species Leuciscus idus melanotus. A LC50 (96 h) > 10 g/L (nominal) was determined at test termination. The available studies on the acute toxicity of the read across substance bis(C12-C13)alkyl-2-hydroxybutandioate (CAS 149144-85-4) to aquatic invertebrates and algae demonstrate no toxicity of the substance. The determined EC50 values were >100 mg/L for Daphnia and algae respectively.

The available acute toxicity data of the read-across substances demonstrate that toxic effects of Diisooctadecyl malate (CAS 67763-18-2) up to the limit of water solubility are not likely. Consequently, additional acute and chronic testing is omitted. Data on the toxicity to microorganisms were used from the toxicity control of the biodegradation study according to OECD 301F (Simon, 2015). A respiration inhibition of activated sludge was not observed and thus the concentration of 100 mg/L of the read-across substance can be used as NOEC (NOEC (14 d) ≥ 100 mg/L).

Based on the result from a structurally related read-across substance (in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5) it can be concluded that Diisooctadecyl malate (CAS 67763-18-2) is will show no toxic effects on freshwater organisms up to the limit of the water solubility (WS: 6.5-13.5 µg/L at 20 °C)