Reaction products from the esterification of neopentylglycol with fatty acids, C16-18 (even numbered) and C18-unsatd. and fatty acids, C18-unsaturated, dimers

Endpoint summary

Additional information

The test substance Reaction products from the esterification of neopentylglycol with fatty acids, C16-18 (even numbered) and C18-unsatd. and fatty acids, C18-unsaturated, dimers is characterised by a low vapour pressure (<0.0001 Pa at 20 °C, SPARC (v4.6)), a low water solubility (<0.05 mg/L at 20 °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 a biodegradation study according to OECD 301B which was performed with a structurally similar substance, the target substance is readily biodegradable (95.6% after 28 d). The selected source substance is a constituent of the target substance (neopentylglycol dioleate). Thus, it is suitable to assess to biodegradation of the target substance.

Based on this result, the target substance will be significantly degraded in sewage treatment plants. 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, 2014). As a result of the high adsorption potential of the substance (log Koc > 5, MCI method, KOCWIN v2.00) 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, 2014). In conclusion, the concentration of the substance in conventional STP effluents is presumably marginal. Due to ready biodegradability and based on the chemical structure, abiotic degradation via hydrolysis is considered as not relevant for the substance. Moreover, the substance is not volatile (VP < 0.0001 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, 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 (Erler, 2015).

Based on the physico/chemical properties such as low water solubility and high potential for adsorption a reduced availability in water is expected. Moreover, the substance is expected to be metabolised in aquatic organisms by breaking the ester bond and metabolisation of the enzymatic hydrolysis products (fatty acid and fatty alcohol). It can be concluded that the bioaccumulation potential of Reaction products from the esterification of neopentylglycol with fatty acids, C16-18 (even numbered) and C18-unsatd. and fatty acids, C18-unsaturated, dimers is negligible. In addition BCF/BAF values estimated by QSAR (BCFBAF v3.01) also support this assumption (BCF values all well below 2000 L/kg). Please refer to IUCLID Section 5.3 for a detailed overview on bioaccumulation of the substance.