Fatty acids, tall-oil, esters with trimethylolpropane

Endpoint summary

Additional information

There are no data available investigating the terrestrial toxicity ofFatty acids, tall-oil, triesters with trimethylolpropane (CAS 94581-09-6). In order to fulfil the standard information requirements, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across from structurally related substances 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 aquatic 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.

 

Ecotoxicological parameters for the terrestrial toxicity of the target and the source substance are provided in the following table.

ID	CAS	Toxicity to soil macroorganisms except arthropods	Toxicity to terrestrial arthropods	Toxicity to terrestrial plants	Toxicity to soil microorganisms
Target	94581-09-6	RA: CAS 68541-50-4 RA: CAS 78-16-0	Data waiving	RA: CAS 68002-79-9	Weight of Evidence
Source 2	68002-79-9	--	--	Experimental result: NOEC (14 d) 300 - 1000 mg/kg dw	--
Source 4	68541-50-4	Experimental result: NOEC (56 d) ≥ 1000 mg/kg	--	--	--
Source 13	78-16-0	Experimental result: NOEC (56 d) ≥ 1000 mg/kg	--	--	--

 

The above mentioned 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 the same endpoints forFatty acids, tall-oil, triesters with trimethylolpropane (CAS 94581-09-6). The target as well as the source substance are all characterized by the same alcohol component (trimethylolpropane) and a similar fatty acid chain lengths (C18:1 for the target substance and C16, C18:1; 18 branched and C7 for the source substances, respectively). All substances are predominantly triesters. The selection of these source substances allow for interpolation to the target substance since the source substances cover the upper and the lower end of C-chain distribution of the target substance. A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

Experimental data on the toxicity of Fatty acids, tall-oil, triesters with trimethylolpropane (CAS 94581-09-6)to terrestrial organisms are available for 2-ethyl-2-[[(1-oxoheptyl)oxy]methyl]propane-1,3-diyl bisheptanoate (CAS 78-16-0), Fatty acids, C16-18 (even numbered) and C16-18-unsatd. (even numbered), triesters with trimethylolpropane (CAS 68002-79-9) and 2-ethyl-2-(((1-oxoisooctadecyl)oxy)methyl)-1,3-propanediyl bis (isooctadecanoate) (CAS 68541-50-4).

The long-term toxicity of the source substances 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) to earthworms was tested in two studies according to OECD guideline 222. The studies focused on the effect of the test substances on earthworm survival, growth and reproduction (Eisner, 2013a,b). Mortality or detrimental effects on earthworm growth were not observed and thus a NOEC (28 d) ≥ 1000 mg/kg soil dw based on mortality. The reproduction rate was determined after another 28 days by counting the number of hatched juveniles. A significant difference to the control was not observed and thus a NOEC (56 d) ≥ 1000 mg/kg was determined based on reproduction.

The short-term toxicity of the source substance Fatty acids, C16-18 (even numbered) and C16-18-unsatd. (even numbered), triesters with trimethylolpropane (CAS 68002-79-9) was tested according to OECD 208. The study determined no toxicity of the substance on the early seedling growth of the tested plant species (NOEC (14 d) = 300 mg/kg for Lycopersicon esculentum and Raphanus sativus respectively, NOEC (14 d) = 1000 mg/kg for Avena sativa).

Generally the available data on the substance and generated from suitable source substances indicate a low bioavailability and a low toxicity to terrestrial organisms. Studies on the short-term and chronic toxicity to aquatic organism determined no toxicity up to the limit of water solubility. The substance is readily biodegradable and thus expected to be largely eliminated in sewage treatment plants by degradation. Furthermore based on the low water solubility (0.6 mg/L at 20 °C for the TMP esters fraction/6.2 mg/L at 20 °C, pH6 for the total soluble fraction) and the high log Koc (> 3) the substance is expected to be mechanically removed in the primary settling tank and fat trap and thus and only limited amounts will get in contact with activated sludge organisms. Consequently, a significant release to the environment via STP effluents is not expected. However, if the substance is released to the environment a rapid degradation is assumed. Since a respiration inhibition of aquatic microorganisms was not observed in the available studies, a comparable result is expected for soil microorganisms. This assumption is supported by several studies investigating the degradation of fatty acid esters by soil microorganisms (Hita et al., 1996, Banchio & Gramajo, 1997 and Cecutti et al., 2002).

The characteristics of Fatty acids, tall-oil, triesters with trimethylolpropane (i.e. low water solubility, low vapour pressure and high log Koc) determine the environmental fate of the substance. A distribution to the soil compartment is most probable. The substance has a potential to adsorb to soil particles and thus might be ingested by soil dwelling organisms. However, toxicity to terrestrial organisms is not expected based on the available data. When ingested the substance is expected to be rapidly metabolised and excreted. Bioaccumulation is not anticipated. This also supported by the low BCF values (BCF: 0.89 - 18.94 L/kg; Arnot-Gobas) calculated for the substance. An uptake through pore water via plant roots is not likely due to the low water solubility and high adsorption potential of the substances.