Fatty acids, C8-10, 3-methylbutyl esters

Short-term toxicity to aquatic invertebrates

Description of key information

No toxic effects up to the limit of water solubility (EU Method C.2)

Additional information

Since no studies are available on the short-term aquatic invertebrate toxicity of Fatty acids, C8-10, 2-methylbutyl esters (CAS No. 1365095-43-7), the assessment was based on a study conducted with the structurally most similar category member, for which data is available, isopropyl myristate (CAS No. 110-27-0) and Fatty acids, C8-16, 2-ethylhexyl esters (CAS No. 135800-37-2) as part of a read-across approach. This is in accordance with Regulation (EC) No 1907/2006, Annex XI, 1.5. Grouping of substance and read across approach. Further justification is given within the endpoint summary 6.1 and within the category justification section 13. In this case of read-across, the best suited (highest degree of structural similarity, nearest physico-chemical properties) read-across substance was entered in IUCLID. Nevertheless, as can be seen in the data matrix of the category justification in Section 13, all reliable data in the category support the hazard assessment for this endpoint, by showing a consistent pattern of results.

The key study with isopropyl myristate (CAS No. 110-27-0) was performed as a limit test according to EU Method C.2 and GLP (Stelter, 1995). The test organism Daphnia magna was exposed to the test substance in a static system for 48 hours. Three different methods were used for the preparation of test solutions: 1) direct addition to 100 mg/L, 2) direct addition to 100 mg/L with removal of undissolved test substance and 3) 3-5 times saturation without separation of undissolved material. With the first method an oil film was observed at the surface, and up to 100% immobilisation occurred. With the other two methods, no significant effect was observed. Based on the results, the observed immobilisation is most probably due to physical effects caused by undissolved test substance. It can therefore be concluded that the test substance had no significant toxic effect on the test organism up to the limit of water solubility. An EC50 of > 0.05 mg/L was reported.

The key study with Fatty acids, C8-16, 2-ethylhexyl esters (CAS No. 135800-37-2) was performed as a limit test, according to EU Method C.2 (Wierich, 1998). The test organism Daphnia magna was exposed to the test substance in a static system for 48 hours. Three different methods were used for the preparation of test solutions: 1) direct addition to 100 mg/L, 2) direct addition to 100 mg/L with removal of undissolved test substance and 3) 3-5 times saturation without separation of undissolved material. With the first treatment daphnids got stuck to oil drops on the surface or to the walls of the vessel. With the second and third treatments no immobilisation was observed, and an EC50 of > 100 mg/L is reported.

Thus, based on theabove mentioned results, and due to the structural and profile similarities of the substances, as are explained with in the overall endpoint summary 6.1 it can be concluded that no toxicological short-term effects on aquatic invertebrates are expected up tothe limit ofwater solubility for Fatty acids, C8-10, 2-methylbutyl esters (CAS No. 1365095-43-7).