Registration Dossier

Diss Factsheets

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

No effects up to the limit of water solubility (OECD 201).

Key value for chemical safety assessment

Additional information

Since no studies investigating the toxicity to aquatic algae of Fatty acids, C16-18, 2-octyldodecyl esters (CAS 96690-38-9) are available for this endpoint, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 a read across to the structurally related category member 2-octyldodecyl isooctadecanoate (CAS 93803-87-3) was conducted. The read-across substance is characterized by the same alcohol component (2-octyldodecan-1-ol) and a very similar fatty acid (C16-18 compared to C18iso (target)). This read-across is justified in detail in the overall summary (IUCLID Section 6.1) and within the category justification in IUCLID Section 13. In this case of read-across, the best suited (highest degree of structural similarity, nearest physico-chemical properties) read-across substances were used for the assessment. Nevertheless, as it can be seen in the data matrix of the category justification in section 13 and the overall summary, all reliable data in the category support the hazard assessment of each category member by showing a consistent pattern of results.

The study with the read-across substance 2-octyldodecyl isooctadecanoate was conducted according to OECD 201 (GLP) with the freshwater algae Selenastrum capricornutum (Bogers, 1998). Water Accommodated Fractions (WAF) of nominal 10 and 100 mg/L were prepared and tested under static conditions.A chemical analysis of the test substance concentrations in the test vessels was not possible since no applicable method could be established due to the very low water solubility to detect test concentrations. An inhibition of growth (31.2%) was observed after 72 h in the WAF test solution of 100 mg/L, whereas no inhibition was observed in the WAF test solution of 10 mg/L. It was reported that this effect is probably related to insoluble particles which might have adsorbed fractions of light needed for algal cell growth. Since both test substance concentrations are above water solubility it can be concluded that the EC50 and the NOEC exceed the maximum water solubility of the test substance. An EL50 of > 100 mg/L and a NOELR of ≥ 100 mg/L were derived.Based on the available result from one structurally related read-across substance (in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5) which is characterized by a similar ecotoxicological profile and comparable structure, it can be concluded that Fatty acids, C16-18, 2-octyldodecyl esters will not exhibit effects to aquatic algae up to the limit of water solubility.