Fatty acids, C16-18 and C18-unsatd., Bu esters

Short-term toxicity to aquatic invertebrates

Description of key information

No effects up to the limit of water solubility for Daphnia magna (OECD 202)

Additional information

Since no studies are available on short-term aquatic invertebrate toxicity of Fatty acids, C16-18 and C18 unsaturated, butyl esters (CAS No. 84988-74-9), the assessment was based on studies conducted with the structurally most similar category members, for which data is available, Fatty acids, C16-18 and C18-unsaturated isobutyl esters (CAS No. 84988-79-4) and Fatty acids, C16-18, butyl esters (CAS No. 85408-76-0) as part of a read-across approach. This read across approach 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 into 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 conducted with Fatty acids, C16-18 and C18-unsaturated isobutyl esters (CAS No. 84988-79-4) was performed as a limit test according to EU guideline 92/69/EWG and GLP (Wierich, 1995). The test organism Daphnia magna was exposed to the test substance in a static system for 48 hours. Three different methods were applied for the preparation of test solutions: 1) direct addition to nominal 100 mg/L without separation of undissolved test material, 2) direct addition to nominal 100 mg/L followed by a separation of undissolved test material and 3) 3 to 5 fold saturation concentration without separation of undissolved material. Immobilisation was observed only in the test solutions prepared using the first method, and was therefore probably due to physical effects caused by the large amount of undissolved test material present in the test solution. With separation of undissolved test material and with 3 to 5 fold saturation no negative effects were observed. It can be concluded that the test substance had no toxic effects on Daphnia magna up to the limit of water solubility. An EL50 of > 100 mg/L is reported.

The key study with Fatty acids, C16-18, Bu esters (CAS No. 85408-76-0) was performed as a limit test according to EU Method C.2 and GLP (Wierich, 1998). The test organism Daphnia magna was exposed to the test organism in a static system for 48 hours, at the nominal test concentration of 100 mg/L, prepared as water accommodated fractions (WAF). No immobilisation was observed at any treatment, and an EC50 of > 100 mg/L was reported.

Thus, based on theabove mentioned results, and due to the structural and profile similarities of the substances, as are explained within 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, C16-18 and C18 unsaturated, butyl esters (CAS No. 84988-74-9).