Fatty acids, tall-oil, esters with dipentaerythritol

Endpoint summary

Additional information

There are no data available investigating the biodegradability of Fatty acids, tall oil, esters with dipentaerythritol (CAS 70913-98-3). In order to fulfil the standard information requirements set out in Annex VII, 8.5, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across from one 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 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 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.

Environmental fate parameters for the target and the source substance are provided in the following table.

CAS	70913-98-3	68604-38-6
Chemical Name	Fatty acids, tall oil, esters with dipentaerythritol	Fatty acids, C16-18 and C18-unsatd., hexaesters with dipentaerythritol
MW	1684.73 - 1840.95	1684.73 - 1840.95
Phototransformation in air [DT50, 24 h day]	(Q)SAR: 46.4 min - 2.87 h	(Q)SAR: 46.4 min - 2.87 h
Hydrolysis [DT50, pH 7]	(Q)SAR: >1 yr	(Q)SAR: >1 yr
Biodegradation: screening tests	RA: CAS 68604-38-6	Experimental result: not readily biodegradable
BCF / BAF [L/kg]	0.89/0.89 (Arnot-Gobas)	0.89/0.89 (Arnot-Gobas)
Adsorption/Desorption [log Koc]	(Q)SAR: 27.6 - 30.72 (MCI)	(Q)SAR: 27.6 - 30.72 (MCI)

 

The above mentioned substances are considered to be similar on the basis of the structural similar properties and/or activities. The available endpoint information is used to predict the same endpoints for Fatty acids, tall oil, esters with dipentaerythritol (CAS 70913-98-3). The target as well as the read-across substance both exhibit same fatty acid chain lengths C16, C18 and C18 unsatd. and the same alcohol component (dipentaerythritol) and are hexa-esters. A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

 

Fatty acids, tall oil, esters with dipentaerythritol (CAS 70913-98-3) is characterised by a low vapour pressure (VP < 0.0001 Pa, SPARC (v4.6)), a low water solubility (<0.04 mg/L; Frischmann, 2013), and a high log Koc indicating a high adsorption potential to soil and sediment particles (log Koc 27.6 - 30.72 MCI method, KOCWIN v2.00). The substance is not readily biodegradable (7.6% (CO2 evolution) after 28 d) based on the structurally similar read-across substance fatty acids, C16-18 and C18-unsatd., hexaesters with dipentaerythritol (CAS 68604-38-6). Nevertheless, it is expected that an extensive elimination of the substance in sewage treatment plants will occur. In the case insoluble chemicals enter a standard Sewage Treatment Plant (STP), they will be extensively removed in the primary settling tank and fat trap and thus, only limited amounts will get in contact with activated sludge organisms, according to the Guidance on information requirements and chemical safety assessment, Chapter R.7b (ECHA, 2012). As a result of the high adsorption potential of the substance (log Koc of 27.6 and 30.7 for the main components of the substance; Kuckuck, 2013) a removal from the water column to a significant degree by adsorption to sewage sludge can be expected (Guidance on information requirements and chemical safety assessment, Chapter R.7b, (ECHA, 2012). In conclusion, the concentration of the substance in conventional STP effluents is presumably marginal. Abiotic degradation via hydrolysis is considered as not relevant for the substance. Calculations using HYDROWIN v2.00 predict half-lives > 1 year for the main components of the substance (Kuckuck, 2013). Moreover, the substance is not volatile (VP < 0.0001 Pa) and thus evaporation to the air and subsequent transport through the atmosphere to other environmental compartments is not likely. However, if Fatty acids, tall oil, esters with dipentaerythritol is released into air, the substance is susceptible to indirect photodegradation in air by OH-radicals as half-lives of less than 24 hours were calculated for the main components of the substance (Kuckuck, 2013). The bioavailability of Fatty acids, tall oil, esters with dipentaerythritol is expected to be negligible due to the predicted environmental fate and high molecular weight of the substance components (MW: 1684 – 1853 g/mol).

Based on the low water solubility and metabolisation via enzymatic hydrolysis of the substance a relevant uptake and bioaccumulation in aquatic organisms is not expected. The amount of Fatty acids, tall oil, esters with dipentaerythritol that has become systemically available, might be hydrolysed and the cleavage products can be further metabolized. However, due to its high molecular weight, absorption of Fatty acids, tall oil, esters with dipentaerythritol is not likely and thus, no extensive metabolism is expected but rather direct elimination. In conclusion, bioaccumulation and biomagnification through the food chain of the substance is not expected. This is supported by a low calculated BCF value of 0.89 L/kg ww (BCFBAF v3.01, Arnot-Gobas, including biotransformation, upper trophic). Please refer to IUCLID Section 5.3 for a detailed overview on bioaccumulation of Fatty acids, tall oil, esters with dipentaerythritol. As it can be seen in the data matrix of the analogue justification in IUCLID Section 13, all reliable data from the target and the source substance support the read-across for the biodegradation endpoint by showing a consistent pattern of results.

 

A detailed reference list is provided in the technical dossier (see IUCLID, section 13) and within the CSR.