Fatty acids, C14-18, C14-18-alkyl esters

Endpoint summary

Additional information

There are no data available investigating the terrestrial toxicity of Fatty acids, C14-18, C14-18-alkyl esters (CAS 85566-24-1). In order to fulfil the standard information requirements, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across from a structurally related substance was conducted.

In accordance with Article 13 (1) of Regulation (EC) No 1907/2006, "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.” In particular for terrestrial toxicity, 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).

Having regard to the general rules for grouping of substances and read-across approach laid down in Annex XI, Item 1.5, of Regulation (EC) No 1907/2006 whereby 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 target and all source substances are considered to be similar on the basis of the structural similar properties and/or activities. The available endpoint information on the source substances is used to predict comparable results for the target substance Fatty acids, C14-18, C14-18-alkyl esters (CAS 85566-24-1).
The target substance is characterized as an ester of mainly C14 fatty acid/C14 alcohol, C16 fatty acid/C14 alcohol and C16 fatty acid/C16 alcohol. The source substance is structurally very similar to the target substance. Fatty acids, C8-10, C12-18-alkyl esters (CAS 95912-86-0) is a UVCB substance consisting of mainly C8-C10 fatty acids esterified with C12-C14 alcohol. A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

Exposure of the soil compartment is generally considered to be low. Even if exposed to the soil the substance is readily biodegradable indicating that it will not be persistent in the environment. Indirect exposure via irrigation or atmospheric transport is considered to be negligible based on the physico-chemical properties of the target substance (water solubility: < 0.02 mg/L at 20 °C, pH 6.3; vapour pressure: <0.0001 Pa).

Experimental data investigating the chronic toxicity of the source substance to earthworms are available. Testing of the toxicity on earthworm evaluates the exposure to the test substance via soil pore water, surface contact as well as by ingestion of soil particles. Due to the high adsorption potential (log Koc > 5) of the substance, long-term testing was considered to be relevant to investigate further the effects of the substance on terrestrial organisms. The available study was performed according to OECD 222. No mortality and no effects on biomass were recorded after 28 d. However, effects on reproduction expressed in the number of juveniles was observed at the highest test concentration of 1000 mg/kg soil dw. Thus, a NOEC (56 d) of 500 mg/kg soil dw was derived. After absorption, the substance is expected to be enzymatically hydrolysed by carboxylesterases yielding to the corresponding alcohol and fatty acid. QSAR estimations using BCFBAF v3.0 support the expected rapid biotransformation of this substance with BCF/BAF values of 0.89 - 0.91 and 0.95 - 23.72 L/kg were obtained, respectively. The metabolism of the hydrolysis products is well established and not of concern in terms of bioaccumulation (for further information see chapter 5.3 of the technical dossier). Summarizing, the substance is expected to be rapidly hydrolysed to the respective fatty acid and fatty alcohol. Both hydrolysis products are supposed to be satisfactory metabolised in terrestrial organisms. Therefore, the potential for bioaccumulation is low. Available acute and chronic aquatic toxicity tests to fish, invertebrates, algae and microorganisms showed no adverse effects occurred in the range of the water solubility (< 0.02 mg/L at 20 °C, pH 6.3). These results support the assumption that the substance is of low toxicity to terrestrial organisms.

The available data for toxicity to aquatic microorganisms from the source substance Fatty acids, C8-10, C12-18-alkyl esters support the determination of a lack of toxicity to soil microorganisms. No inhibition of respiration rate of activated sludge microorganisms was observed in the available study. The Guidance Document (ECHA, 2014, page 136) states that a test on soil microbial activity will only be additionally necessary for a valid PNEC derivation if inhibition of sewage sludge microbial activity has occurred and this is clearly not the case. This is supported by further evidence from literature data. This data showed that soil microorganism communities are well capable of degrading fatty acid esters (Hita et al., 1996 and Cecutti et al., 2002) and use them as energy source (Banchio & Gramajo, 1997). Based on the available information, effects on soil microorganisms are not expected to be of concern, and consequently, no further testing is required.

In conclusion Fatty acids, C14-18, C14-18-alkyl esters (CAS 85566-24-1) is of low toxicity to terrestrial organisms based on all available data.

References

Banchio, C. and Gramajo, H. C. (1997). Medium- and long-chain fatty acid uptake and utilization by Streptomyces coelicolor A3 (2): first characterization of a Gram-positive bacterial system. Microbiology 143 (Pt 7), 2439-2447.

Cecutti, C., Agius, D., Caussade, B., Gaset, A. (2002). Fate in the soil of an additive of plant origin. Pest Management Science 58(12): 1236-1242.

ECHA (2014c). Guidance on information requirements and chemical safety assessment, Chapter R.7c: Endpoint specific guidance. European Chemicals Agency, Helsinki.

Hita, C.; Parlanti, E.; Jambu, P.; Joffre, J.; Amblès, A. (1996). Triglyceride degradation in soil. Org. Geochem 25(1-2): 19-28.