Fatty acids, C14-22, C16-24-alkyl esters

Endpoint summary

Additional information

There is no data available for the aquatic toxicity of the target substance fatty acids, C14-22, C16-24-alkyl esters (CAS 92797-30-3). Therefore, the aquatic toxicity of the target substance was assessed by read-across to three structurally and chemically closely related source substances in order to fulfill the standard information requirements laid down in Annex XI, 1.5 of the REACh Regulation (EC) No 1907/2006.

According to Article 13 (1) of this regulation, "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.” For aquatic toxicity in particular, 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). In regard to the general rules for grouping of substances and the read-across approach, the regulation specifies (Annex XI, Item 1.5) that substances may be predicted as similar provided that their physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity.

The source substances are characterized by fatty acid esters of similar chain lengths and are therefore considered suitable representatives for the assessment of the toxicity of the target substance to aquatic organisms. A detailed justification of the analogue approach is provided in IUCLID section 13.

By means of the read-across approach to the selected source substances, GLP guideline studies are available for the assessment of the aquatic toxicity of the target substance fatty acids, C14-22, C16-24-alkyl esters (CAS 92797-30-3), covering the short-term toxicity to all three trophic levels (fish, aquatic invertebrates and algae) as well as the long-term toxicity to two trophic levels (aquatic invertebrates and algae). The compiled data for acute and chronic toxicity neither indicate any short-term nor any long-term toxicity towards aquatic organisms up to the limit of water solubility of the sources substances (< 0.05 mg/L). Furthermore, no toxic effects towards microorganisms of activated sludge were observed.

Given the extremely low water solubility of the target substance (< 2.5 µg/L, 20 °C, OECD 105), long-term testing on aquatic invertebrates was considered necessary to fully assess the potential aquatic hazard. The available read-across study for chronic toxicity to aquatic invertebrates was performed with the source substance (Z)-octadec-9-enyl oleate (CAS 3687-45-4) and showed no effects on the reproduction ofD. magnaup to the limit of water solubility (< 0.05 mg/L) after 21 d of exposure.

Due to the ready biodegradability and high adsorption potential, the target substance is expected to be eliminated from sewage treatment plants to a high extent. Release to surface waters and subsequent exposure of sediment is therefore highly unlikely. In the unexpected event in which absorption by aquatic organisms should occur, the substance is expected to be rapidly metabolized via enzymatic hydrolysis into its corresponding fatty acids and fatty alcohols, which are known form literature to metabolize well in aquatic organisms. Against this background, the potential for chronic exposure is judged to be very low.

Therefore, it can be concluded that fatty acids, C14-22, C16-24-alkyl esters (CAS 92797-30-3) presumably does not exhibit short-term or long-term effects to aquatic organisms up to the limit of water solubility (< 2.5 µg/L) and is not expected to affect the degradation process in commercial sewage treatment plants.