Fatty acids, C6-12, mixed tetraesters with heptanoic acid, pentaerythritol, 3,5,5-trimethylhexanoic acid and valeric acid

Endpoint summary

Additional information

There are no data available on the biodegradation of Pentaerythritol tetraesters of n-C5, n-C7, n-C8, i-C9 and n-C10 fatty acids (EC 451-190-0). In order to fulfil the standard information requirements set out in Annex VII, 9.2.1.1, 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 a suitable source substance was selected for hazard assessment.

Based on the specification the target substance Pentaerythritol tetraesters of n-C5, n-C7, n-C8, i-C9 and n-C10 fatty acids (EC 451-190-0) is characterized by the alcohol component pentaerythritol tetraesterified with mainly fatty acids of C5, C7, C8, C9iso and C10. The source substance, selected to cover biodegradation, is specified as followed: Reaction product of pentaerythritol and trimethylolpropane with n-pentanoic acid, 2-methylbutyric acid, n-heptanoic acid, 3,5,5-trimethylhexanoic acid, n-octanoic acid and n-decanoic acid (Source 3, hereafter referred to as PE/TMP tetra/tri C5, i-C5, C7, C8, i-C9, C10 ester) consisting of pentaerythritol tetraesters and trimethylolpropane triesters with the same fatty acids as specified for the target substance.

The target substance Pentaerythritol tetraesters of n-C5, n-C7, n-C8, i-C9 and n-C10 fatty acids (EC 451-190-0) is characterised by a low vapour pressure (0.0062 Pa at 20 °C), a low water solubility (< 1 mg/L at 25 °C) and a high log Koc indicating a high adsorption potential to soil and sediment particles (log Koc > 5, MCI method, KOCWIN v2.00). Based on the result from the selected source substance, the target substance is readily biodegradable (62% (CO2 evolution) after 28 d (OECD 301B). Thus, 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, 2012b). As a result of the high adsorption potential of the substance 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, 2012b). 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 since it is readily biodegradable. Moreover, the substance is not volatile (vapour pressure: 0.0062 Pa at 20 °C) and thus evaporation to the air and subsequent transport through the atmosphere to other environmental compartments is not likely. However, if the substance is released into air, it 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 (Szymoszek, 2014).

The substance has a log Pow ≥ 7 (OECD 107) indicating a potential for bioaccumulation. But due to the low water solubility and rapid environmental biodegradation, a relevant uptake and bioaccumulation in aquatic organisms is not expected.Overall, the part of Pentaerythritol tetraesters of n-C5, n-C7, n-C8, i-C9 and n-C10 fatty acids 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 Pentaerythritol tetraesters of n-C5, n-C7, n-C8, i-C9 and n-C10 fatty acids is not likely and thus, no extensive metabolism is expected but rather direct elimination which indicates a low potential for bioaccumulation.Additional information can be gathered from BCF/BAF calculation using BCFBAF v3.01. The estimated BCF value indicates a low bioaccumulation in organisms as well. When including biotransformation rate constants a BCF of 0.89 - 6.322 and a BAF of 0.89 - 6.323 L/kg resulted (Arnot-Gobas estimate, including biotransformation, upper trophic). Please refer to IUCLID Section 5.3 for a detailed overview on bioaccumulation. But taking all information into account, the bioaccumulation of the substance is assumed to be low.

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 by showing a consistent pattern of results.