Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

No acute toxicity effects to aquatic invertebrates up to the limit of water solubility.

Key value for chemical safety assessment

Additional information

In general, all EC/EL50(48h) values derived with different invertebrate species for various test substances in the SCAE C2 -C8 category were above the limit of water solubility, so that no toxicity of dissolved substance was found (chemical toxicity). There were, however, several studies describing indirect toxicity by means of physical effects of the test substance at concentrations between 1 and 100 mg/L.

No studies are available for Fatty acids, C16-18, 2 -ethylhexyl esters. Therefore, results are taken from the read-across substances 2-ethylhexyl oleate (CAS 26399-02-0), Fatty acids, C8 -16, 2 -ethylhexyl esters (CAS 135800-37-2) and Fatty acids, C16-18 and C18-unsatd., 2-ethylhexyl esters (CAS 85049-37-2).

One key study investigated the effects of the read across 2-ethylhexyl oleate to the freshwater invertebrate Daphnia magna (Kuech and Wierich 1995). The study was performed according to the EU-method C.2 considering the VCI concept draft for the acute testing of poorly soluble substances from 1994-01-31 for 48 h. The first approach without removal of the insoluble particles resulted in immobilization rates between 0 and 100% (mean: 25%). After removal of insoluble particles (filtration) no effects to Daphnia magna were observed. Thus, it can be stated that the insoluble particles of the test substance resulted in negative physical effects to the test species (e.g. agglutination of gills). No effects in the range of water solubility were observed. This resulted in an EC50 (48h) > 100 mg/L (nominal).

The second key study determined the acute toxicity of the read across substance Fatty acids, C8 -16, 2 -ethylhexyl esters to Daphnia magna according to the EU method C.2 under GLP conditions (Wierich 1998). Different mixing methods of test solution with dilution water were applied. Effects on mobility of the daphnids (about 50 %) were reported for the medium which contained 100 mg/L test substance without further separation of the undissolved test substance (measured concentration at the start of the test: 12.41 mg/L). After filtration of the test solution no effect on mobility was stated (measured concentration at the start of the test: 0.04 mg/L). Similarly to the first read across, these results confirmed the statement, that the observed effects are most likely physical and not systemic effects. The resulting EC50(48h) was reported as >100 mg/L (nominal).

A supporting study on the marine species Acartia tonsa as category read-across from Fatty acids, C16-18 and C18-unsatd., 2-ethylhexyl esters (CAS 85049-37-2), tested as WAF, reported an EL50(48h) > 2047 (1646 -2470) mg/L (Hudson 2000).