Fatty acids, C14-18 and C16-18-unsatd., mixed esters with castor oil, castor oil fatty acids, 2-ethylhexanoic acid and 2,2-bis(hydroxymethyl)-1-butanol

Endpoint summary

Additional information

Justification for grouping of substances and read-across

There are no valid data available on the chronic toxicity towards terrestrial macroorganisms of Fatty acids, C14-18 and C16-18-unsatd., mixed esters with castor oil, castor oil fatty acids, 2-ethylhexanoic acid and 2,2-bis(hydroxymethyl)-1-butanol (CAS No. 92113-48-9). In order to fulfill the standard information requirements set out in Annex VIII, Section 8.5.2, in accordance with Annex XI, Section 1.5 of Regulation (EC) No 1907/2006, read-across from structurally similar substances is 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 human 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 physicochemical, toxicological and ecotoxicological properties may be predicted from data for reference substance(s) by interpolation to other substances on the basis of structural similarity, the substances 2-ethyl-2-(((1-oxoisooctadecyl) oxy)methyl)-1,3-propanediyl bis (isoocta decanoate) (CAS No. 68541-50-4) and 2-ethyl-2-[[(1-oxoheptyl)oxy]methyl]propane-1,3-diyl bisheptanoate (78-16-0) are selected as reference substances for the assessment of chronic toxicity towards earthworm.

The read-across is based on structural similarity as all chemicals are polyol fatty acid ester with trimethyl propane as common alcohol component. A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

Overview of terrestrial toxicity for the target substance Fatty acids, C14-18 and C16-18-unsatd., mixed esters with castor oil, castor oil fatty acids, 2-ethylhexanoic acid and 2,2-bis(hydroxymethyl)-1-butanol (CAS No. 92113-48-9) and the source substances is presented in the following table.

	Target substance (a)	Source substance (b)	Source substance
CAS No.	92113-48-9	68541-50-4	78-16-0
Chemical name	Fatty acids, C14-18 and C16-18-unsatd., mixed esters with castor oil, castor oil fatty acids, 2-ethylhexanoic acid and 2,2-bis(hydroxymethyl)-1-butanol	2-ethyl-2-(((1-oxoisooctadecyl) oxy)methyl)-1,3-propanediyl bis (isoocta decanoate)	2-ethyl-2-[[(1-oxoheptyl)oxy]methyl]propane-1,3-diyl bisheptanoate
Toxicity to soil macroorganisms except arthropods	RA: CAS 68541-50-4 RA: CAS 78-16-0	Experimental result: NOEC (56d) = 1000 mg/kg	Experimental result: NOEC (56d) = 1000 mg/kg
Toxicity to terrestrial arthropods	Data waiving	--	--
Toxicity to terrestrial plants	Data waiving	--	--
Toxicity to soil microorganisms	Data waiving	--	--

(a) The substance subject to the REACh Phase-in registration deadline of 31 May 2013 is indicated in bold font. Only for this substance a full set of experimental results and/or read-across is given.

(b) Reference (read-across) substance(s) are indicated in normal font. Lack of data for a given endpoint is indicated by “--“.

Discussion:

Experimental data on the toxicity of Fatty acids, C14-18 and C16-18-unsatd., mixed esters with castor oil, castor oil Fatty acids, 2-ethylhexanoic acid and 2,2-bis(hydroxymethyl)-1-butanol (CAS No. 92113-48-9) to terrestrial organisms are not available. In accordance with Regulation (EC) No. 1907/2006, Annex IX, column 2, 9.4 further studies on the effects on terrestrial organisms does not have to be conducted since the chemical safety assessment indicates that there is no need. The substance is characterised by a high Koc indicating a high potential to adsorb to soil particles. Therefore the substance might be ingested by soil-dwelling organism feeding on soil particles. However, the substance is in all probability not acutely toxic as indicated by the available studies on the acute toxicity to aquatic organisms. A chronic exposure of terrestrial organisms is not likely since the substance is readily biodegradable. Thus, it can be expected to be rapidly and ultimately degraded in the terrestrial environment. When ingested by soil dwelling organisms, the substance is expected to be metabolised and thus an accumulation and/or chronic effects are not likely. Acute effects to soil microorganisms are not expected since the available data on aquatic microorganisms indicate no detrimental effects. An inhibition of respiration rate of aquatic microorganisms was not observed in the available study for this substance. In addition, two earthworm reproduction tests according to OECD 222 are available for the read across TMP esters 2-ethyl-2-[[(1-oxoheptyl)oxy]methyl]propane-1,3-diyl bisheptanoate (CAS 78-16-0) and 2-ethyl-2-(((1-oxoisooctadecyl)oxy)methyl)-1,3-propanediyl bis (isooctadecanoate) (CAS 68541-50-4). In both studies no chronic toxicity of the substances to Eisenia fetida was determined (Eisner, 2013). The substances caused neither mortality nor a decrease in body weight of adult earthworms. Also the reproduction rates were not affected by the TMP esters and thus a NOECmort/repro 1000 mg/kg was reported in both studies. Thus, in accordance with Regulation (EC) No. 1907/2006, Annex X, Column 2, 9.4 further studies on the effects on terrestrial organisms do not have to be conducted since the chemical safety assessment indicates that toxicity to terrestrial organisms is not expected to be of concern.